The materials reviewed for Open Up Resources K–5 Math Grade 1 meet expectations for developing conceptual understanding of key mathematical concepts, especially where called for in specific content standards or cluster headings.

Materials develop conceptual understanding throughout the grade level. According to the Grade 1 Course Guide, Design Principles, conceptual understanding is a part of the design of the materials. Balancing Rigor states, “There are three aspects of rigor essential to mathematics: conceptual understanding, procedural fluency, and the ability to apply these concepts and skills to mathematical problems with and without real-world contexts. These aspects are developed together and are therefore interconnected in the materials in ways that support student understanding. Opportunities to connect new representations and language to prior learning support students in building conceptual understanding. Access to new mathematics and problems prompts students to apply their conceptual understanding and procedural fluency to novel situations.” Additionally, Purposeful Representations states, “Across lessons and units, students are systematically introduced to representations and encouraged to use representations that make sense to them. As their learning progresses, students are given opportunities to make connections between different representations and the concepts and procedures they represent.” Examples include:

• Unit 1, Adding, Subtracting, and Working with Data, Section A, Lesson 2, Activity 2, Launch, students develop conceptual understanding as they write addition expressions for sums within ten. Launch states, “Groups of 2. Give each group a set of cards, two recording sheets, and access to 10-frames and two-color counters. ‘We are going to learn a game called Check It Off. Let’s play a round together. First we take out all of the cards greater than five. We will not use those cards in this game. Now I am going to pick two number cards and find the sum of the numbers. The sum is the total when adding two or more numbers.’ Choose two cards. ‘What is the sum of the numbers? How do you know?’ 30 seconds: quiet think time. 1 minute: partner discussion. Share responses. ‘Now I check off the sum. What addition expression represents the sum of the numbers?’ 30 seconds: quiet think time. Share responses. ‘I record the expression on my recording sheet next to the sum. Now it’s my partner’s turn.’” (1.OA.5, 1.OA.6)

• Unit 3, Adding and Subtracting Within 20, Section B, Lesson 13, Activity 1, Launch and Student Work Time, students develop conceptual understanding as they solve Take From, Change Unknown story problems using a method of their choice. Launch states, “Groups of 2. Give students access to double 10-frames and connecting cubes or two-color counters. Display and read the numberless and questionless story problem. ‘What do you notice? What do you wonder?’ 30 seconds: quiet think time. 1 minute: partner discussion. Record responses. If needed, ‘What question could we ask?’ In Student Work Time, Student Facing states, “1. There are students standing in the classroom. Some of the students sit down on the rug. There are still some students standing. 2. There are 15 students standing in the classroom. Some of the students sit down on the rug. There are still 5 students standing. How many students sat down on the rug? Show your thinking using drawings, numbers, or words. Equation: ___.” (1.OA.1, 1.OA.5, 1.OA.6)

• Unit 8, Putting It All Together, Lesson 9, Warm-up, Student Work Time, students develop conceptual understanding as they use true and false statements to compare two-digit numbers. Student Facing states, “Decide if each statement is true or false. Be prepared to explain your reasoning. $65>35$, $65=75-10$, $65>35+30$.” (1.NBT.3)

According to the Grade 1 Course Guide, materials were designed to include opportunities for students to independently demonstrate conceptual understanding, when appropriate. Design Principles, Coherent Progress states, “Each activity starts with a launch that gives all students access to the task. This is followed by independent work time that allows them to grapple with problems individually before working in small groups. The activity ends with a synthesis to ensure students have an opportunity to consolidate their learning by making connections between their work and the mathematical goals.” A Typical Lesson states, “The Cool-down task is to be given to students at the end of the lesson. Students are meant to work on the Cool-down for about 5 minutes independently and turn it in. The Cool-down serves as a brief formative assessment to determine whether students understood the lesson. Students’ responses to the Cool-down can be used to make adjustments to further instruction.” Examples include:

• Unit 3, Adding and Subtracting Within 20, Section A, Lesson 2, Cool-down, students show a conceptual understanding of addition facts. Student Facing states, “How does knowing $7+2=9$ help you with $2+7=$___? Show your thinking using drawings, numbers, or words.” (1.OA.3) 

• Unit 5, Adding Within 100, Section C, Lesson 12, Activity 2, Student Work Time and Activity Synthesis, students demonstrate conceptual understanding as they use what they know about the base-ten structure of numbers to create different expressions. Students are provided counting cubes. In Student Work Time, Student Facing states, “37, 22, 18, 56, 41. Choose 2 numbers from above and write an addition expression to make each statement true. a. This sum has the smallest possible value. Expression: ____ b. This sum has the largest possible value. Expression: ____ c.You do not need to make a new ten to find the value of this sum. Expression: ____ d. If you make a new ten to find the value of this sum, you will still have some more ones. Expression: ____ e. If you make a new ten to find the value of this sum, you will have no more ones. Expression: ____ Be ready to explain your thinking in a way that others will understand. f. If you have time: Choose 2 numbers from above and write an addition expression where the value is closest to 95. How do you know the value is closest to 95?” Activity Synthesis states, “Are there other numbers you could use? How do you know?” (1.NBT.C)

• Unit 8, Putting It All Together, Section C, Lesson 8, Activity 1, Launch, students demonstrate conceptual understanding as they represent numbers within 100 using drawings, words, numbers, expressions, and equations. Launch states, “Give each student a piece of blank paper and access to connecting cubes in towers of 10 and singles. ‘We are going to create a class book. First you will plan out your page. Pick your favorite number between 20 and 100. You will represent your number in as many different ways as you can. You need to include at least three expressions. Let’s make a page together.’ Display the number 84. ‘What are some ways that I can represent this number?” (I can draw 8 tens and 4 ones, 7 tens and 14 ones, $80+4$, $10+10+10+10+10+10+10+10+4.70+14$) 30 seconds: quiet think time. 1 minute: partner discussion. Record responses. If needed, ask: ‘How can we represent 84 using only 6 tens? What other addition expressions could we write?’” (1.NBT.B)

The materials reviewed for Open Up Resources K–5 Math Grade 1 meet expectations for giving attention throughout the year to individual standards that set an expectation of procedural skill and fluency. 

According to the Grade 1 Course Guide, Design Principles, Balancing Rigor, “Warm-ups, practice problems, centers, and other built-in routines help students develop procedural fluency, which develops over time.” Examples include: 

• Unit 1, Adding, Subtracting, and Working with Data, Section A, Lesson 2, Activity 1, Student Work Time, students develop procedural fluency as they match expressions to dot images and find the total. Student Work Time states, “‘In this activity, draw a line to connect each dot image to its matching expression. Then, find the total. On the second page, complete the missing expressions or the missing dot images.’ 5 minutes: independent work time, ‘Share your work with your partner.’ 3 minutes: partner discussion” Student Facing states, “1. Match each pair of dots to an expression. Then, find the total. 2. Draw the missing dots to match the expression. Then, find the total. 3. Write the missing expression to match the dots. Then, find the total.” Expressions include: $3+2$, $4+2$, $5+3$, $6+4$, $4+3$. (1.OA.6)

• Unit 3, Adding and Subtracting Within 20, Section A, Lesson 5, Warm-up, Student Work Time, students develop procedural fluency as they select numbers that make an equation true. Student Facing states, “Find the number that makes each equation true. $6+$___$=10$, $10-6=$___, $8+$___$=10$, $10-2=$___.” (1.OA.6, 1.OA.8) 

• Unit 6, Length Measurements Within 120 Units, Section A, Lesson 2, Warm-up, Student Work Time, students develop procedural fluency as they add numbers within 100. Student Facing states, “Find the value of each expression mentally. $35+20$, $35+25$, $30+45$, $37+45$.” (1.NBT.4) 

According to the Grade 1 Course Guide, materials were designed to include opportunities for students to independently demonstrate procedural skill and fluency, when appropriate. Design Principles, Coherent Progress states, “Each activity starts with a launch that gives all students access to the task. This is followed by independent work time that allows them to grapple with problems individually before working in small groups. The activity ends with a synthesis to ensure students have an opportunity to consolidate their learning by making connections between their work and the mathematical goals.” A Typical Lesson states, “The Cool-down task is to be given to students at the end of the lesson. Students are meant to work on the Cool-down for about 5 minutes independently and turn it in. The Cool-down serves as a brief formative assessment to determine whether students understood the lesson. Students’ responses to the Cool-down can be used to make adjustments to further instruction.” Examples include:

• Unit 3, Adding and Subtracting Within 20, Section A, Lesson 2, Activity 3, Student Work Time, students demonstrate fluency by finding the value of sums within 10. In Student Work Time, Student Facing states, “Find the value of each sum. a. $7+2=$___ b. $3+5=$___ c. ___$=8+2$ d. $3+6=$___ e. $5+2=$___ f. ___$=4+4$ g. $2+6=$___ h. ___$=1+9$.” Student Work Time states, “Read the task statement. 5 minutes: independent work time. 3 minutes: partner discussion.” (1.OA.5, 1.OA.6, 1.OA.8)

• Unit 4, Numbers to 99, Section A, Lesson 4, Activity 2, Student Work Time, students demonstrate procedural skill and fluency as they practice adding and subtracting multiples of 10 from multiples of 10. In Student Work Time, Student Facing states, “e. $20+60=$___ f. $70-20=$___ g. $90-70=$___ h. $40+40=$___.” Student Work Time states, “5 minutes: independent work time. 5 minutes: partner work time.” (1.NBT.2c, 1.NBT.4, 1.NBT.6) 

• Unit 8, Putting It All Together, Section A, Lesson 2, Cool-down, students demonstrate procedural fluency by using the subtraction and addition relationship to add or subtract within 10. Student Facing states, “Mai is still working on $9-6=$___. Write an addition equation she can use to help figure out the difference. Addition equation: ___.” (1.OA.6)

The materials reviewed for Open Up Resources K–5 Math Grade 1 meet expectations for being designed so that teachers and students spend sufficient time working with engaging applications of mathematics. 

According to the Grade 1 Course Guide, Design Principles, Balancing Rigor, “Access to new mathematics and problems prompts students to apply their conceptual understanding and procedural fluency to novel situations.” Multiple routine and non-routine applications of the mathematics are included throughout the grade level, and these single- and multi-step application problems are included within Activities or Cool-downs. 

Students have the opportunity to engage with applications of math both with teacher support and independently. According to the Grade 1 Course Guide, materials were designed to include opportunities for students to independently demonstrate application of grade-level mathematics, when appropriate. Design Principles, Coherent Progress states, “Each activity starts with a launch that gives all students access to the task. This is followed by independent work time that allows them to grapple with problems individually before working in small groups. The activity ends with a synthesis to ensure students have an opportunity to consolidate their learning by making connections between their work and the mathematical goals.” A Typical Lesson states, “The Cool-down task is to be given to students at the end of the lesson. Students are meant to work on the Cool-down for about 5 minutes independently and turn it in. The Cool-down serves as a brief formative assessment to determine whether students understood the lesson. Students’ responses to the Cool-down can be used to make adjustments to further instruction.”

Examples of routine applications of the math include:

• Unit 2, Addition and Subtraction Story Problems, Section A, Lesson 2, Activity 2, Student Work Time, students solve and write equations for Result Unknown word problems. Student Work Time states, “‘Now you will solve the problems and write equations to match. You can solve the problems in any way that makes sense to you.’ Read problems aloud. 5 minutes: partner work time. ‘Find another group and discuss each problem. Share the equation you wrote and how it matches the story.’ 5 minutes: small-group discussion.” Student Facing states, “a. There was a stack of 6 books on the table. Someone put 4 more books in the stack. How many books are in the stack now? Show your thinking using drawings, numbers, or words. Equation: ___ b. 9 books were on a cart. The librarian took 2 of the books and put them on the shelf. How many books are still on the cart? Show your thinking using drawings, numbers, or words. Equation: ___ c. 2 kids were working on an art project. 7 kids join them. How many kids are working on the art project now? Show your thinking using drawings, numbers, or words. Equation:___ d. The librarian had 8 bookmarks. He gave 5 bookmarks to kids at the library. How many bookmarks does he have now? Show your thinking using drawings, numbers, or words. Equation: ___.” (1.OA.1)

• Unit 3, Adding and Subtracting within 20, Section C, Lesson 20, Cool-down, students solve real-world word problems with three addends. Student Facing states, ”Jada visited the primate exhibit. She saw 8 monkeys, 4 gorillas, and 7 orangutans. How many primates did she see? Show your thinking using drawings, numbers, or words. Equation: ___.” (1.OA.2, 1.OA.6)

• Unit 4, Numbers to 99, Section A, Lesson 4, Activity 1, Launch and Student Work Time, students solve story problems involving adding and subtracting multiples of 10. Launch states, “Groups of 2. Give students access to connecting cubes in towers of 10 and singles and double 10-frames.” Student Work Time states, “Read the task statement. 7 minutes: independent work time. 3 minutes: partner discussion. Monitor for students who show: towers of 10, base-ten drawings, ___ tens and ___ tens, expressions or equations.” In Student Work Time, Student Facing states, “a. Jada is counting collections of cubes. In Bag A there are 30 cubes. In Bag B there are 2 towers of 10. How many cubes are in the two bags all together? Show your thinking using drawings, numbers, or words. b. Tyler is counting a collection of cubes. In Bag C there are 7 towers of 10. He takes 40 cubes out of the bag. How many cubes does he have left in the bag? Show your thinking using drawings, numbers, or words.” (1.NBT.2c, 1.NBT.4, 1.NBT.6)

Examples of non-routine applications of the math include:

• Unit 3, Adding and Subtracting Within 20, Section D, Lesson 28, Activity 1, Launch and Student Work Time, students generate, articulate, and solve their own addition and subtraction problems. Launch states, “Give students access to double 10-frames and connecting cubes or two-color counters. Display and read the questionless story problem. ‘What is this story missing? What kind of questions could you ask? (How many pencils did they have altogether? How many more pencils does Noah have than Elena?)’ 30 seconds: quiet think time. 1 minute: partner discussion. Share and record responses. ‘We have been solving different kinds of story problems. Today, you and your partner will write and solve addition and subtraction story problems using objects we have in our classroom.’” Student Work Time states, “‘Partner A will pick a number less than 20. Partner B will use objects in the room to write a story problem and ask a question for which the number Partner A picked is the answer. Together, solve the story problem and write an equation. Switch roles for problem 2.’ 10 minutes: partner work time.” In Student Work Time, Student Facing states, “Noah had 8 pencils. Elena had 5 pencils. Han had 4 pencils..a Addition story problem: Solve the story problem. Show your thinking using drawings, numbers, or words. Equation: ___ b. Subtraction story problem: Solve the story problem, Show your thinking using drawings, numbers, or words. Equation: ___.” (1.OA.1, 1.OA.2, 1.OA.3, 1.OA.6)

• Unit 5, Adding Within 100, Section B, Lesson 8, Activity 3, Student Work Time, students solve story problems involving addition with two-digit and one-digit numbers. Student Work Time states, “Read the task statement. 3 minutes: independent work time. 3 minutes: partner discussion.” Student Facing states, “a. Priya watched a football game. The home team scored 35 points in the first half. In the second half they scored 6 more points. How many points did they score all together? Show your thinking using drawings, numbers, or words. b. At the football game, 9 fans cheered for the visiting team. There were 45 fans who cheered for the home team. How many fans were at the game all together? Show your thinking using drawings, numbers, or words.” (1.NBT.4)

• Unit 6, Length Measurements Within 120 Units, Section B, Lesson 7, Cool-down, students solve a problem by reasoning about measurements with different units. Student Facing states, “Priya says that the length of the shoe is 5 paper clips. Is her measurement accurate? Why or why not?” An image of a high-top sneaker is shown with 5 paper clips. (1.MD.2)

The materials reviewed for Open Up Resources K–5 Math Grade 1 meet expectations in that the three aspects of rigor are not always treated together and are not always treated separately. There is a balance of the three aspects of rigor within the grade.

All three aspects of rigor are present independently throughout the grade. Examples where instructional materials attend to conceptual understanding, procedural skill and fluency, or application include:

• Unit 2, Addition and Subtraction Story Problems, Section C, Lesson 14, Activity 1, Launch and Student Work Time, students analyze and solve addition and subtraction application problems. Launch states, “Groups of 2, ​​Give students access to connecting cubes or two-color counters. Display the image in the student book. ‘Tell a story about this picture.’ 1 minute: quiet think time. 2 minutes: partner discussion. Share responses.” In Student Work Time, Student Facing states, “There are 8 glue sticks and 3 scissors at the art station. How many fewer scissors are there than glue sticks? Mai created a picture. (An Image of eight red dots and three yellow dots is provided.) She is not sure which equation she should use to find the difference. $8-3=5$, $3+5=8$, Help her decide. Show your thinking using drawings, numbers, or words.” (1.OA.1, 1.OA.5, 1.OA.7)

• Unit 3, Adding and Subtracting Within 20, Section A, Lesson 4, Activity 2, Student Work Time and Activity Synthesis, students develop conceptual understanding as they justify that they have found all the ways to make 10. An image of 10 counters in a ten frame is displayed. Students have access to counters and a 10-frame. In Student Work Time, Student Facing states, “a. Show all the ways to make 10.  b. How do you know that you have found all the ways? Be ready to explain your thinking in a way that others will understand.” Activity Synthesis states, “‘How do you know that you found all of the ways?’ (I started by filling my 10-frame with red counters and then flipped over the first red counter to make it yellow. That was $1+9$. I kept flipping over a one red counter at a time to make it yellow and kept writing expressions.)” (1.OA.3, 1.OA.6)

• Unit 7, Geometry and Time, Section C, Lesson 15, Activity 2, Launch and Student Work Time, students develop procedural fluency as they write times after reading one or both hands on a clock. Launch states, ”Groups of 2, Give students their Half Past Clock Cards. ‘Write the times on the new clock cards that show half past.’ 2 minutes: independent work time.” Student Work Time states, “What time is shown on each clock? Work on the questions by yourself and then compare your work with your partner’s.” In Student Work Time, Student Facing states, “1. For each clock, write the time. a. Clock shows 2:00. b. Clock shows 4:30. c. Clock shows 6:30. d. Clock shows 12:00. e. Clock shows 8:00.” (1.MD.3)

Multiple aspects of rigor are engaged simultaneously throughout the materials in order to develop students’ mathematical understanding of a single unit of study or topic. Examples include:

• Unit 1, Adding, Subtracting, and Working with Data, Section B, Lesson 8, Activity 2, Launch and Student Work Time, students develop conceptual understanding alongside procedural fluency as they sort shapes into categories and explain their strategies for sorting. Launch states, “Give students access to colored pencils or crayons and copies of the three-column table.” In Student Work Time, Student Facing states, “a. Show how you sorted the shape cards. Be sure that someone else who looks at your paper can see how many shapes are in each category. b. Complete the sentences: 1. The first category has ___ shapes. 2. The second category has ___ shapes. 3. The third category has ___ shapes. 4. There are ___ shapes all together.” (1.MD.4)

• Unit 3, Adding and Subtracting Within 20, Section A, Lesson 6, Activity 1, Student Work Time, students develop conceptual understanding alongside application as they use addition to solve routine problems. In Student Work Time, Student Facing states, “Han is playing Shake and Spill. He has some counters in his cup. Then he puts 3 more counters in his cup. Now he has 10 counters in his cup. How many counters did he start with? Show your thinking using drawings, numbers, or words. Equation: ___.” (1.OA.1, 1.OA.5, 1.OA.6)

• Unit 6, Length Measurements Within 120 Units, Section A, Lesson 1, Activity 2, Launch, Student Work Time, and Activity Synthesis, students develop all three aspects of rigor, conceptual understanding, procedural skill and fluency, and application as they order objects by length. Launch states, “Groups of 4, Give each group 10–12 objects.” In Student Work Time, Student Facing states, “a. Pick 3 objects. With your partner, put the objects in order from shortest to longest. Trace or draw your objects. b. Pick 3 new objects. With your partner, put them in order from longest to shortest. Write the names of the objects in order from longest to shortest.” Activity Synthesis states, “Invite previously identified students to demonstrate how they ordered three objects from shortest to longest. Display the three objects with the endpoints lined up so all students can see. ‘What statements can you make to compare the length of their objects?’ (The ___ is longer than the ___ and ___.)” (1.MD.1)

The materials reviewed for Open Up Resources K–5 Math Grade 1 meet expectations for supporting the intentional development of MP1: Make sense of problems and persevere in solving them; and MP2: Reason abstractly and quantitatively, for students, in connection to the grade-level content standards, as expected by the mathematical practice standards. 

Students have opportunities to engage with the Math Practices across the year, and they are often explicitly identified for teachers within the Course Guide (How to Use These Materials). A chart is provided within this section that highlights several lessons that showcase particular Mathematical Practices. The Mathematical Practices are also identified within specific lessons (Lesson Preparation Narratives and Lesson Activities’ Narratives).

MP1 is identified and connected to grade-level content, and there is intentional development of the MP to meet its full intent. Students make sense of problems and persevere in solving them as they work with support of the teacher and independently throughout the units. Examples include:

• Unit 2, Addition and Subtraction Story Problems, Section A, Lesson 4, Cool-down, students make sense of story problems and write equations. Student Facing, “Mai has 3 books. She gets some more books from the library. Now she has 7. How many more books did she get? Show your thinking using drawings, numbers, or words. Equation:___.” Preparation, Lesson Narrative states, “This lesson provides an opportunity to assess student progress on making sense of different types of story problems, the methods they use to solve, and the equations they write to match the problems.”

• Unit 3, Adding and Subtracting Within 20,Section C, Lesson 15, Activity 1, Launch, Student Work Time, and Activity Narrative, students solve a story problem with three addends in which two of the addends make 10. Launch states, “Groups of 2. Give students access to double 10-frames and connecting cubes or two-color counters. ‘What kind of birds do you see where you live? Where do you see the birds?’ (I see pigeons on wires. I see a big bird in the park. I see red birds at the bird feeder. I hear loud birds in the morning.). 30 seconds: quiet think time. 1 minute: partner discussion. Share and record responses. Write the authentic language students use to describe the birds they see and where they see them. ‘Louis Fuertes was a bird artist. When he was a child, he loved to paint the birds he saw.’ Consider reading the book The Sky Painter by Margarita Engle. ‘We are going to solve some problems about birds.’'' Student Work Time states, “3 minutes: independent work time. 2 minutes: partner discussion. As students work, consider asking: ‘How are you finding the total number of birds? How did you decide the order to add the numbers? Is there another way you can add the numbers?’ Monitor for students who use the methods described in the narrative.” In Student Work Time, Student Facing states, “7 blue birds fly in the sky. 8 brown birds sit in a tree. 3 baby birds sit in a nest. How many birds are there altogether? Show your thinking using objects, drawings, numbers, or words.” An image of a blue bird is shown. Activity Narrative states, “Students are given access to double 10-frames and connecting cubes or two-color counters. Students read the prompt carefully to identify quantities before they start to work on the problem. They have an opportunity to think strategically about which numbers of birds to combine first since 3 and 7 make 10. They also may choose to use appropriate tools such as counters and a double 10-frame strategically to help them solve the problem (MP1, MP5).”

• Unit 6, Length Measurements Within 120 Units, Section C, Lesson 17, Activity 2, students make sense of addition and subtraction word problems. Launch states, “Take turns reading a problem you came up with in the previous activity. Your partner group will act out the story with connecting cubes, then solve the problems. Then switch roles.” In Student Work Time, Student Facing states, “1. Group A: Read your problems to your partner group. 2. Group B: a. Act out and solve the problems. Show your thinking using drawings, numbers, or words. b. Write an equation to represent each story problem. c. What do you notice about the story problems and the equations you wrote?” Activity Narrative states, “The purpose of this activity is for students to solve addition and subtraction word problems by acting out the stories. Acting out gives students opportunities to make sense of a context (MP1).”

MP2 is identified and connected to grade-level content, and there is intentional development of the MP to meet its full intent. Students reason abstractly and quantitatively as they work with support of the teacher and independently throughout the units. Examples include:

• Unit 2, Addition and Subtraction Story Problems, Section B, Lesson 6, Activity 2, Launch, Student Work Time, and Activity Narrative, students consider two different equations that represent the same story problem. Launch states, “Groups of 2. Give students access to 10-frames and connecting cubes or two-color counters. ‘We just solved a problem about pet fish. What else do you know about pets?’ 30 seconds: quiet think time. 1 minute: partner discussion. If needed ask, ‘What kinds of pets are there?’ Student Work Time states, “Read the task statement. 3 minutes: independent work time. 2 minutes: partner discussion. Monitor for a student who uses objects or drawings to show that each equation matches the story.” In Student Work Time, Student Facing states, “Tyler and Clare want to know how many pets they have together. Tyler has 2 turtles. Clare has 4 dogs. Tyler wrote the equation  $4+2=6$. Clare wrote the equation $2+4=6$. Do both equations match the story? Why or why not? Show your thinking using drawings, numbers, or words.” Activity Narrative states, “Students contextualize the problem and see that each number represents a specific object’s quantity, no matter which order it is presented, and connect these quantities to written symbols (MP2).”

• Unit 5, Adding Within 100, Section C, Lesson 14, Activity 1, Launch, Student Work Time, and Activity Narrative, students solve two-digit addition word problems. Launch states, “Give students access to connecting cubes in towers of 10 and singles. The table shows the number of cans four students collected for their class’ food drive. ‘What do you notice? What do you wonder?’ (They collected a lot of cans. Tyler collected the most. Han collected the least. I wonder how many they collected all together.)” Student Work Time states, “Read the task statement. 6 minutes: independent work time. ‘Check in with your partner. Be prepared to show or explain your thinking.’ 5 minutes: partner discussion.” In Student Work Time, Student Facing states, “a. Partner A: Write an equation to represent your thinking. How many cans did Lin and Priya collect altogether? How many cans did Han and Tyler collect altogether?  How many cans did all four students collect altogether? b. Partner B: Write an equation to represent your thinking. How many cans did Tyler and Priya collect altogether?  How many cans did Lin and Han collect altogether?  How many cans did all four students collect altogether?” Activity Narrative states, “The purpose of this activity is for students to apply their understanding of place value and properties of operations to solve two-digit addition real world problems (MP2). Students may use any method and representation that helps them make sense of the problems in context.”

• Unit 8, Putting It All Together, Section B, Lesson 5, Activity 1, Launch, Student Work Time, and Activity Narrative, students solve addition and subtraction story problems. Launch states, “Groups of 2. Give each group access to connecting cubes in towers of 10 and singles. Display the image in the student book. ‘What do you notice in this picture? What do you wonder? (There are bright colors. This looks like stars in the sky. Why is there red in the sky? Where is this?). This is a picture of something called the Helix Nebula. It is one of many interesting things that can be seen in our sky. People who are interested in learning more about stars, planets, or anything else that is found in the sky, can visit a planetarium to learn all about these things. We are going to solve some problems about a field trip to the planetarium.’” Student Work Time states, “8 minutes: independent work time. 4 minutes: partner discussion. Monitor for students who solve the problem about bright and dim stars with addition and for students who solve the same problem with subtraction.” In Student Work Time, Student Facing states, “Solve each problem. Show your thinking using drawings, numbers, or words. a. There are 7 first graders and some second graders at the planetarium. There are 18 students at the planetarium. How many second graders are at the planetarium? b. When the show started, 18 stars lit up in the sky. 13 stars were bright. Some of the stars were dim. How many stars were dim? c. Together, Diego and Tyler saw 15 shooting stars during the show. Diego saw 6 shooting stars. Tyler saw the rest. How many shooting stars did Tyler see? d. In the gift shop, Elena bought 12 star stickers. She also bought some planet stickers. Elena bought 20 stickers. How many planet stickers did she buy?” Activity Narrative states, “The purpose of this activity is for students to make sense of and solve Put Together/Take Apart, Addend Unknown story problems (MP2). In the synthesis, students discuss different methods used to solve these problems, including using addition and subtraction.”

The materials reviewed for Open Up Resources K–5 Math Grade 1 meet expectations for supporting the intentional development of MP3: Construct viable arguments and critique the reasoning of others, for students, in connection to the grade-level content standards, as expected by the mathematical practice standards. 

Students have opportunities to engage with the Math Practices across the year, and they are often explicitly identified for teachers within the Course Guide (How to Use These Materials). A chart is provided within this section that highlights several lessons that showcase particular Mathematical Practices. The Mathematical Practices are also identified within specific lessons (Lesson Preparation Activity Narratives and Lesson Activities’ Activity Narratives).

According to the Grade 1 Course Guide, Design Principles, Learning Mathematics By Doing Mathematics, “Students learn mathematics by doing mathematics, rather than by watching someone else do mathematics or being told what needs to be done. Doing mathematics can be defined as learning mathematical concepts and procedures while engaging in the mathematical practices - making sense of problems, reasoning abstractly and quantitatively, making arguments and critiquing the reasoning of others, modeling with mathematics, making appropriate use of tools, attending to precision in their use of language, looking for and making use of structure, and expressing regularity in repeated reasoning. By engaging in the mathematical practices with their peers, students have the opportunity to see themselves as mathematical thinkers with worthwhile ideas and perspectives.”

Students construct viable arguments, in connection to grade-level content, as they work with support of the teacher and independently throughout the units. Examples include:

• Unit 3, Adding and Subtracting Within 20, Section A, Lesson 6, Activity 2, Student Work Time and Activity Narrative, students construct arguments as they solve addition and subtraction stories. In Student Work Time, Student Facing states, “a. Noah is playing Shake and Spill with 10 counters. 4 of the counters fall out of the cup. How many counters are still in the cup? Show your thinking using drawings, numbers, or words. Equation: ____.” Activity Narrative states, “During the synthesis, students focus on sharing equations and comparing the start and change unknown problems, as well as how the commutative property can help them solve story problems with an unknown start. As students discuss and justify their decisions, they share a mathematical claim and the thinking behind it (MP3).”

• Unit 5, Adding Within 100, Section A, Lesson 1, Activity 1, Launch and Student Work Time, students construct viable arguments as they apply their place value understanding to add an amount of tens or ones to a two-digit number. Launch states, “Groups of 2. Give each group a set of number cards and a paperclip. Give students access to connecting cubes in towers of 10 and singles. ‘Remove the 0, 6, 7, 8, 9 and 10 from the number cards. We are going to play a game where you must figure out the number your partner added. Let’s play a round together. All of you are partner A and I am partner B.’ Invite a student to spin. ‘You spun (43). I will draw a number card and decide whether to add that many ones or that many tens. I will say the sum aloud. The sum is (93). What number did I add? Talk with your partner. Be ready to explain how you know.’ (You added 50. In order to get from 43 to 93 you add 5 tens. 53, 63, 73, 83, 93.) 1 minute: partner discussion. Share responses.” Student Work time states, “‘Now you will play with your partner. For each round, decide whether you will add tens or ones and see if your partner can guess what you added.’ 15 minutes: partner work time. As students work, consider asking: ‘How did you choose to add tens or ones? How did you determine the number your partner added?’” In Student Work Time, Student Facing states, “Partner A: Spin to get a starting number. Partner B: Pick a number card without showing your partner. Choose whether to add that many ones or tens to your starting number. Make sure you don't go over 100. Tell your partner the sum. Partner A: Tell your partner what number you think they added and explain your thinking. Switch roles and repeat.” Activity Narrative states, “Throughout the activity, students explain how they add and how they determined the unknown addend with an emphasis on place value vocabulary (MP3).”

• Unit 8, Putting It All Together, Section C, Lesson 8, Cool-down, students construct arguments as they interpret representations of numbers up to 100. Student Responses states, “Represent numbers to show the base-ten structure. Represent the same number with different amounts of tens and ones.” Preparation, Lesson Narrative states, “Students represent a two-digit number in as many ways as they can. They are encouraged to think about representations of their number that have different amounts of tens. Then, they do a gallery walk to compare representations their classmates made.”

Students critique the reasoning of others, in connection to grade-level content, as they work with support of the teacher and independently throughout the units. Examples include:

• Unit 1, Adding, Subtracting, and Working with Data, Section B, Lesson 7, Activity 1, Launch, Student Work Time, and Activity Narrative, students begin to critique the reasoning of others as they sort math tools and understand how a partner sorted the tools. Launch states, “Groups of 2, Give each group a bag of math tools and access to the blackline masters.” Student Work Time states, “‘Sort your math tools. Use the tables if they are helpful.’ 4 minutes: partner work time. ‘Explain to another group how you sorted your tools. Make sure to tell them the groups you used and how many objects are in each group.’ 3 minutes: small group discussion. MLR2 Collect and Display. Circulate, listen for, and collect the language students use to describe how they sorted. Listen for categories, the number of shapes in each category, and math tool names. Record students’ words and phrases on a poster titled ‘Words to describe how we sorted’ and update throughout the lesson.” Activity Narrative states, “Students identify attributes of the objects and sort them into two or more groups. Students may choose to use one of the blackline masters to organize as they sort. When students share how they sorted with their partner, they use their own mathematical vocabulary and listen to and understand their partner's thinking (MP3, MP6).”

• Unit 3, Adding and Subtracting Within 20, Section C, Lesson 19, Activity 1, Launch, Student Work Time, and Activity Narrative, students create an argument and critique the reasoning of others as they analyze methods for adding within 20 and use those methods flexibly to find sums. Launch states, “Groups of 2, Give students access to double 10-frames and connecting cubes or two-color counters.” Student Work Time states, “Read the task statement. ‘Use double 10-frames and counters to determine how each method works. Show your thinking in a way that others will understand.’ 10 minutes: partner work time. 3 minutes: partner discussion. Monitor for students who can explain each method using 10-frames.”  In Student Work Time, Student Facing states, “Lin, Han, and Kiran are finding the value of $8+7$. (An image of a double ten frame, eight red counters, and seven yellow counters are shown.) Lin thinks about  $8+2+5$. Han thinks about $7+7+1$. Kiran thinks about $8+8-1$. Explain how each student’s method works. Show your thinking using drawings, numbers, or words.”  Activity Narrative states, “Throughout this activity, students must justify and explain the work of the given characters. Students share their thinking and have opportunities to listen to and critique the reasoning of their peers (MP3).”

• Unit 4, Numbers to 99, Section B, Lesson 6, Activity 2, Launch, Student Work Time, and Activity Narrative, students construct an argument and critique reasoning when they analyze a collection of connecting cubes arranged in towers of 10. Launch states, “Groups of 2. Give students access to connecting cubes in towers of 10 and singles. ‘Noah counted a collection of connecting cubes. He says there are 50 cubes. Do you agree or disagree? Explain how you know. You will have a chance to think about it on your own and talk to your partner about Noah’s thinking before you write your response.’” Student Work Time states, “1 minute: quiet think time. ‘Share your thinking with your partner.’ 2 minutes: partner discussion. ‘Explain why you agree or disagree with Noah. Write the word “agree” or “disagree” in the first blank. Then write why you agree or disagree.’ 3 minutes: independent work time.” In Student Work Time, Student Facing states, “Noah organized his collection of connecting cubes. He counts and says there are 50 cubes. Do you agree or disagree? Explain how you know. I ___ with Noah because.” Activity Narrative states, “When students explain that they disagree with Noah because a ten must include 10 ones, they show their understanding of a ten and the foundations of the base-ten system (MP3).”

The materials reviewed for Open Up Resources K–5 Math Grade 1 meet expectations for supporting the intentional development of MP4: Model with mathematics; and MP5: Choose tools strategically, for students, in connection to the grade-level content standards, as expected by the mathematical practice standards. 

Students have opportunities to engage with the Math Practices across the year, and they are often explicitly identified for teachers within the Course Guide (How to Use These Materials). A chart is provided within this section that highlights several lessons that showcase particular Mathematical Practices. The Mathematical Practices are also identified within specific lessons (Lesson Preparation Instructional Routines and Lesson Activities’ Instructional Routines).

MP4 is identified and connected to grade-level content, and there is intentional development of the MP to meet its full intent. Students have many opportunities to solve real-world problems, model situations with appropriate representations, and describe what they do with the model and how it relates to the problem. Students model with mathematics as they work with support of the teacher and independently throughout the units. Examples include:

• Unit 2, Addition and Subtraction Story Problems, Lesson 1, Cool-down, Section A Checkpoint, students represent and solve Add To and Take From, Result Unknown story problems using a strategy that makes sense to them. They also write an expression to represent the action in a story problem. Teachers observe in order to capture evidence of student thinking using the checkpoint checklist. Student Response states, “Retell the story. Represent a story problem with objects or drawings. Explain how a representation matches the story.” Preparation, Lesson Narrative states, “When students connect expressions back to the story problem and explain the connection, they model with mathematics (MP4).”

• Unit 4, Numbers to 99,Section D, Lesson 23, Activity 1, Student Work Time, Launch, and Instructional Routine, students apply their place value understanding to estimate quantities of objects and accurately count familiar objects. Student Facing states, “Experiment 1: How many objects are in 2 handfuls? a. Record an estimate that is: too low, about right, too high. b. Now find the exact number ___. Experiment 2: How many objects are in 2 handfuls? a. Record an estimate that is: too low, about right, too high. b. Now find the exact number ___. Experiment 3: How many objects are in 2 handfuls? a. Record an estimate that is: too low, about right, too high. b. Now find the exact number ___.”  Launch states, “Groups of 2, Display for all to see approximately 15–25 beans or other small objects. ‘How many objects do you think are in this pile?’ 1 minute: partner discussion. Share responses. ‘How could we find out exactly?’ (Count them.).” Student Work Time states, “‘How many objects are in 2 handfuls? Let's do an experiment.’ Give each group a bag of objects. ‘Take turns and grab a handful. Estimate how many objects you both grabbed altogether. Then find out how many you have exactly. You will do this experiment three times.’ 5 minutes: partner work time. Monitor for students who: count by ones group the objects into groups of 10 and then count the tens and ones.” Preparation, Lesson Narrative states, “When students recognize the mathematical features of familiar real world objects and solve problems, they model with mathematics (MP4).”

• Unit 8, Putting It All Together, Section B, Lesson 6, Activity 2, Student Work Time and Instructional Routine, students use given information to ask and answer different questions. In Student Work Time, Student Facing states, “Write and answer 2 questions using the information. Use the picture for the first one if it is helpful. a. Diego went on 7 rides. Priya went on 11 rides. b. Jada went on 3 rides. Kiran went on 6 rides. Noah went on 9 rides.” Instructional Routine states, “When students recognize the mathematical features of things in the real world and ask questions that arise from a presented situation, they model with mathematics (MP4).”

MP5 is identified and connected to grade-level content, and there is intentional development of the MP to meet its full intent. Students have multiple opportunities to identify and use a variety of tools or strategies, working with the support of the teacher and independently, throughout the units to support their understanding of grade-level math. Examples include:

• Unit 4, Numbers to 99, Section A, Lesson 1, Activity 2, Launch, Student Work Time, and Instructional Routine, students organize and count a collection of 40 objects. Launch states, “Groups of 2. Give each group a bag of objects. Give students access to double 10-frames, cups, paper plates, or other tools to help organize a count. ‘Now you will work with your partner to count more collections. Each partner will show on paper how many there are and show how you counted.’” Student Work Time states, “5 minutes: partner work time. ‘Switch bags with another group. Work with your partner to count the collection. Each partner will show on paper how many there are and show how you counted them.’ 5 minutes: partner work time. As students work, consider asking: ‘How can you use what we learned in the last Student Work Time to help you organize your count? Tell me about what you have written here. How many does it show? Does your representation match how you counted?’ Monitor for students who organize objects into groups of ten using cups, paper plates, or other tools, groups using double 10-frames.” Instructional Routine states, “The purpose of this activity is for students to practice counting and representing collections with multiples of 10 objects. Students count one bag with their partner. When students have finished counting and recording, they trade bags with a different group and count a new collection. During the launch, teachers may choose to provide time for students to reflect on how they worked together in the previous activity. During the synthesis, students discuss using a tool that organizes the objects in groups of ten, and how that is helpful when counting a collection.”

• Unit 5, Adding Within 100, Lesson 6, Activity 2, Launch, Student Work Time and Lesson Narrative, students add one-digit and two-digit numbers and deepen their understanding of place value. Student Facing, “Elena and Andre found the value of $34 + 9$. a. Elena started with $34 + 6 = 40$. What does Elena need to do next? Show your thinking using drawings, numbers, or words. b. Andre started with $9 + 1 = 10$. What does Andre need to do next? Show your thinking with drawings, numbers, or words. c. Find the value of $6 + 68$ . Show your thinking using drawings, numbers, or words. Launch, “Give students access to connecting cubes in towers of 10 and singles. Display $34 + 9$. “Elena and Andre found the value of $34 + 9$ . Elena showed her first step by writing $34 + 6 = 40$. What do you notice about her first step?” (She only added 6. Maybe she wanted to make the next ten. She wanted to make a ten with $4 + 6$.) 30 seconds: quiet think time. 1 minute: partner discussion. “What does she need to do to finish her work?” (She needs to add 9 in all. She added 6, now she needs to add 3 more to 40.) 2 minutes: independent work time. 1 minute: partner discussion. Record student thinking as equations $(34 + 6 + 3 = 43)$. “Where do you see 9 in this equation?” $(6 + 3)$. Student Work Time, “Display and read Andre’s first step. “Now decide what Andre needs to do next. Then find the value of  using any method that makes sense to you. Show your thinking with drawings, numbers or words.” 4 minutes: independent work time. 3 minutes: partner work time. Monitor for students who represent composing a ten in different ways, including with connecting cubes and with different equations.” Lesson Narrative, “Completing the start of a calculation as students do here requires critically analyzing, understanding, and expressing different strategies (MP3). Students then have an opportunity to add using one of these methods and the representations that make sense to them. Monitor for students who show composing a new unit of ten using connecting cubes or base-ten diagrams. Students use appropriate tools strategically as they choose which tools help them add (MP5).”

• Unit 6, Length Measurements within 120, Section B, Lesson 8, Activity 1, Launch, Student Work Time, students measure a length that is over 100 length units long and count the number of units using grouping methods. Launch states, “Groups of 3–4. Give each group 120 base-ten cubes, string, and scissors. ‘Today we are going to measure the height of one of your group members. Choose whose height you will measure and cut a piece of string that is the same length as their height.’ 2 minutes: small-group work.” Student Work Time states, “‘Measure the length of the string using small cubes. Represent the measurement using drawings, numbers, or words.’ 15 minutes: partner work time. Monitor for groups who: have measurements between 100–110 cubes, created groups of ten to organize the cubes.” In Student Work Time, Student Facing states, “Represent your measurement using drawings, numbers, or words.” In Preparation, Lesson Narrative states, “The purpose of this lesson is for students to count a quantity between 100 and 110. In the first Student Work Time, students measure how tall they are using base-ten cubes and represent their work in a way that makes sense to them (MP5).”

The materials reviewed for Open Up Resources K–5 Math Grade 1 meet expectations for supporting the intentional development of MP6: Attend to precision; and attend to the specialized language of mathematics, for students, in connection to the grade-level content standards, as expected by the mathematical practice standards. 

Students have opportunities to engage with the Math Practices across the year, and they are often explicitly identified for teachers within the Course Guide (How to Use These Materials). A chart is provided within this section that highlights several lessons that showcase particular Mathematical Practices. The Mathematical Practices are also identified within specific lessons (Lesson Preparation Narratives and Lesson Activities’ Narratives).

Students have many opportunities to attend to precision and the specialized language of math, in connection to grade-level content, as they work with support of the teacher and independently throughout the units. Examples include:

• Unit 1, Adding, Subtracting and Working with Data, Section B, Lesson 7, Warm-up, Launch, and Activity Synthesis, students describe attributes of mathematical objects. Activity Narrative states, “The activity provides an opportunity for students to describe mathematical objects in different ways, including non-mathematical characteristics such as color as well as mathematical characteristics such as the number of corners and the category or properties of the shapes. (MP6). If possible, display the objects themselves rather than the image or provide students with a set of the objects. Some students may not know the names of the shapes. Prompt them to use the language that makes sense to them.” Launch states, “Groups of 2. Display the image. ‘What do you notice? What do you wonder?’ 1 minute: quiet think time.” Activity Synthesis states, “How are the shapes alike? How are they different?”

• Unit 4, Numbers to 99, Section B, Lesson 10, Cool-down, students attend to precision as they write numbers using their knowledge of base-ten representations. Student Facing states, “Write the number that matches each representation. a. $30+9$,  b. an image of 63 base ten blocks, c. 7 ones + 9 tens.” Activity Narrative (for Activity 1) states, “Students must attend to the units in each representation and the meaning of the digits in a two-digit number, rather than always writing the number they see on the left in a representation in the tens place and the number they see on the right in a representation in the ones place (MP6).”

• Unit 4, Numbers to 99, Section C, Lesson 14, Activity 1, Student Work Time, Launch, and Activity Synthesis, students use precise mathematical language as they determine which number is greater and represent their number in any way they choose. In Student Work Time, Student Facing states, “Each partner spins a spinner. Each partner shows the number any way they choose. Compare with your partner. Which number is more?” Launch states, “Groups of 2, Give each group two paper clips and access to connecting cubes in towers of 10 and singles. Display 35 and 52. ‘Which number is more? Show your thinking using math tools. Be ready to explain your thinking to your partner.’ 2 minutes: independent work time. 2 minutes: partner discussion. ‘Which is more and how do you know?’ (53 is more because it has more tens than 35.).” Student Work Time states, “Read the task statement. ‘Each partner can choose to use Spinner A or B for each turn.’ 10 minutes: partner work time.” Activity Narrative states, “Listen for the way students use place value understanding to compare the numbers and the language they use to explain how they know one number is more than the other (MP3, MP6). In the synthesis, students are introduced to the terms greater than and less than.” Activity Synthesis states, “‘Are there any other words or phrases that are important to include on our display?’ As students share responses, update the display by adding (or replacing) language, diagrams, or annotations. Remind students to borrow language from the display as needed. Display 93 and 26. ‘Which is more? How do you know? (93 is more because 9 tens is more than 2 tens.) We can say, ‘93 is greater than 26.’ We can also say, ‘26 is less than 93.’” Display 62 and 64. ‘Which number is more? How do you know? (64 is more. They both have 6 tens but 64 has 4 ones and that is more than the 2 ones in 62.) We can say that 64 is greater than 62. We can also say 62 is less than 64.’”

• Unit 5, Adding Within 100, Section A, Lesson 3, Cool-down, students use precision as they explain how to add expressions. Student Facing states, “Find the value of $14+53$. Show your thinking using drawings, numbers, or words. Write equations to show how you found the value.” Preparation, Lesson Narrative states, “In this lesson, students add two-digit numbers using methods of their choice and write equations to match their thinking. Students interpret and compare different methods for finding the value of the same sums. Students also practice explaining their own methods and listening to the methods of their peers. Students have opportunities to revise how they explain their own and others' methods and consider how representations of their own thinking (for example, drawings or equations) can help them explain or interpret their work (MP3, MP6).”

• Unit 6, Length Measurements Within 120 Units, Section A, Lesson 3, Activity 2, Student Work Time and Launch, students attend to precision when they compare the length of two objects using a third object. In Student Work Time, Student Facing states, “a. Will the teacher’s desk fit through the door? Show your thinking using drawings, numbers, or words. b. Will a student desk fit through the door? Show your thinking using drawings, numbers, or words. c. Which is longer, the bookshelf or the rug? Show your thinking using drawings, numbers, or words. d. Which is longer, the file cabinet or the bookshelf? Show your thinking using drawings, numbers, or words. e. Which is shorter, the bookshelf or the teacher’s desk? Show your thinking using drawings, numbers, or words. f. Will the teacher’s desk fit next to the bookshelf? Show your thinking using drawings, numbers, or words.” Launch states, “Groups of 2. Give students access to measuring materials. ‘Have you ever seen someone move a large piece of furniture, like a couch, from one room to another? Is it easy to move big pieces of furniture? Why or why not?’ 30 seconds: quiet think time. Share responses. ‘I have been thinking about getting a new desk. If I do, I will have to move this desk out of the room. I am not sure if this desk will fit through the door. How can we check to see if it will fit?’ (We could measure with a string.). 30 seconds: quiet think time. 1 minute: partner discussion. Share responses. ‘You are all going to check to see if my desk will fit through the door. You are also going to compare the length of some other objects in the room.” Student Work Time states, “15 minutes: partner work time. Monitor for a group that measures the width of the teacher's desk and one that measures the length.” Activity Narrative states, “When students decide if the teacher's desk will fit through the door or compare other large pieces of furniture, they will need to be precise about which lengths they are measuring as objects like the teacher's desk, a rug, and a bookcase, have a length, width, and in some cases a height (MP6).”

• Unit 7, Geometry and Time, Section A, Lesson 3, Launch, and Activity Synthesis, students use specialized language as they compare attributes of shapes. Activity Narrative states, “This Warm-up prompts students to compare four shapes. It gives students a reason to use language precisely (MP6). It gives the teacher an opportunity to hear how students use terminology and talk about characteristics of two- and three-dimensional shapes.” Launch states, “Groups of 2. Display the image ‘Pick one that doesn’t belong. Be ready to share why it doesn’t belong.’ 1 minute: quiet work time” Activity Synthesis states, “Let’s find at least one reason why each one doesn’t belong. What solid shapes do the images for A, B, and C show? (cube, cone, and cylinder) Does D show a solid shape? Why or why not? (Maybe it is supposed to be a sphere. It looks like it is just a circle.) A circle is not one of our solid shapes. We call it a flat shape.”

The materials reviewed for Open Up Resources K–5 Math Grade 1 meet expectations for supporting the intentional development of MP7: Look for and make use of structure; and MP8: Look for and express regularity in repeated reasoning, for students, in connection to grade-level content standards, as expected by the mathematical practice standards. 

Students have opportunities to engage with the Math Practices across the year, and they are often explicitly identified for teachers within the Course Guide (How to Use These Materials). A chart is provided within this section that highlights several lessons that showcase particular Mathematical Practices. The Mathematical Practices are also identified within specific lessons (Lesson Preparation Narratives and Lesson Activities’ Narratives).

MP7 is identified and connected to grade-level content, and there is intentional development of the MP to meet its full intent. Students have many opportunities to look for, describe, and make use of patterns within problem-solving as they work with support of the teacher and independently throughout the units. Examples include:

• Unit 2, Addition and Subtraction Story Problems, Section D, Lesson 18, Activity 1, Student Work Time and Activity Synthesis, students look for and make use of structure as they interpret equations with a symbol for the unknown and connect them to story problems. Student Work Time states, “‘You have two sets of cards. One set of cards has the story problems we used in the last lesson. The other set of cards has equations with unknown values. Work with your partner to match the story problems to the equations. One story has more than one equation. Be sure you can explain how you know they match.’ 10 minutes: partner work time.” Activity Synthesis states, “‘Which equation matches Card C? How do you know?’ ($9-6=$__. 9 represents how many students were sliding. 6 represents how many students leave so that is $9-6$. The box represents how many are left, which is the answer to the problem.) Repeat for problems F and H. Display equation cards 6 and 8. ‘What do you notice about these equations? (They both have a total of 9 and one part is 4. The other part is the unknown. They both match problem G.). How does each of these equations match the story problem?’ (There are 9 students jumping Double Dutch and 4 students jumping on their own. I need to find the difference, so I can subtract $9-4$ to find the answer or I can say that $9=4+$___. 9 equals 4 plus some more students.).” Activity Narrative states, “The purpose of this activity is for students to match story problems to equations with a symbol for the unknown (MP2). Each equation is written to match the way the numbers are presented in the story problem. Problem G has more than one equation, which prompts students to discuss the relationship between addition and subtraction (MP7). During the synthesis, students discuss how an equation with a symbol for the unknown matches a Take From, Result Unknown story problem.”

• Unit 5, Adding Within 100, Section A, Lesson 1, Warm-up, Student Work Time and Activity Synthesis, students look for and make use of structure as they subitize or use grouping strategies to describe the images they see. In Student Work Time, Student Facing states, “How many do you see? How do you see them?” Activity Synthesis states, “How did we describe the second image using tens and ones? How many tens do you see? How many ones? (Some people said they saw it as 3 tens and 5 ones.) How could we describe the last image using tens and ones? (3 tens and 9 ones) How could we write equations to go with the last image? ($35+4$ or $30+9$).”Preparation, Lesson Narrative states, “When students look for ways to see and describe numbers as groups of tens and ones and connect this to two-digit numbers, they look for and make use of the base-ten structure (MP7).”

• Unit 7, Geometry and Time, Lesson 14, Cool-down, students look for and make use of structure as they learn about the position of the hands on an analog clock at half past the hour. Student Facing states, “Circle the clock that shows 2:30.” Activity 2 Narrative states, “The purpose of this activity is for students to connect their understanding of half of a circle to the minute hand moving halfway around the face of a clock (MP7).”

MP8 is identified and connected to grade-level content, and there is intentional development of the MP to meet its full intent. Students have multiple opportunities to use repeated reasoning in order to make generalizations and build a deeper understanding of grade-level math concepts as they work with support of the teacher and independently throughout the units. Examples include:

• Unit 3, Adding and Subtracting Within 20, Section C, Lesson 17, Cool-down, students use repeated reasoning to add within 20. Students see that they can decompose one addend in order to make a ten. Student Facing states, “8 birds are sitting in a tree. 6 birds are sitting on the grass. How many birds are there all together? Show your thinking using drawings, numbers, or words. Equation: ___.” Lesson Narrative states, “When students identify and use equivalent expressions, they look for and make use of structure (MP7) and here they repeatedly make a 10 to find the value of expressions (MP8).”

• Unit 4, Numbers to 99, Lesson 7, Section A, Activity 1, Student Work Time and Activity Synthesis, students use repeated reasoning to extend their understanding of teen numbers as a ten and some ones to an understanding of all two-digit numbers as some tens and some ones. In Student Work Time, Student Facing states, “Partner 1 draws 2 number cards and uses them to make a two-digit number. Each partner says the number. Partner 2 builds the number using cubes. Partner 1 checks to see if they agree. Each partner makes a drawing of the number and records how many tens and ones. Switch roles and repeat.” Student Work Time states, “10 minutes: partner work time. As students work, consider asking: ‘How do you say this two-digit number? What is your plan for building the number? How many tens does this number have? How many ones does this number have?’” Activity Synthesis states, “Display the number 24 and a base-ten drawing of 4 tens and 2 ones. ‘Tyler made a drawing of 24. Do you agree with how he showed 24? Why or why not? (No, because he drew 4 tens and 2 ones instead of 2 tens and 4 ones. He made the number 42 instead of 24.). Tyler’s drawing shows 42, not 24. They both have the digits 2 and 4, but they are in different places, which makes them different numbers.’” Activity Narrative states, “Students choose two number cards and create a two-digit number. As they build the two-digit numbers with towers of 10 and singles, students see that each two-digit number is composed of a number of tens and a number of ones (MP8).”

• Unit 6, Length Measurements Within 120 Units, Section A, Lesson 4, Warm-up, Student Work Time and Activity Synthesis, students use repeated reasoning to make ten to find sums within 50. In Student Work Time, Student Facing states, “Find the value of each expression mentally. $9+6$, $29+6$, $39+7$, $39+9$.” Activity Narrative states, “When students notice how they can make a ten when finding the value of each expression or when they use one sum to find the value of the next sum, they look for and make use of structure and express regularity in repeated reasoning (MP7, MP8).” Activity Synthesis states, “Did anyone have the same method but would explain it differently? Did anyone approach the problem in a different way?”

The materials reviewed for Open Up Resources K-5 Math Grade 1 meet expectations for providing teachers guidance with useful annotations and suggestions for how to enact the student materials and ancillary materials, with specific attention to engaging students in order to guide their mathematical development.

Within the Course Guide, several sections (Design Principles, A Typical Lesson, How to Use the Materials, and Key Structures in This Course) provide comprehensive guidance that will assist teachers in presenting the student and ancillary materials. Examples include but are not limited to:

• Resources, Course Guide, Design Principles, Learning Mathematics by Doing Mathematics, “A problem-based instructional framework supports teachers in structuring lessons so students are the ones doing the problem solving to learn the mathematics. The activities and routines are designed to give teachers opportunities to see what students already know and what they can notice and figure out before having concepts and procedures explained to them. The teacher has many roles in this framework: listener, facilitator, questioner, synthesizer, and more.”

• Resources, Course Guide, A Typical Lesson, “A typical lesson has four phases: 1. a warm-up; 2. one or more instructional activities; 3. the lesson synthesis; 4. a cool-down.” “A warm-up either: helps students get ready for the day’s lesson, or gives students an opportunity to strengthen their number sense or procedural fluency.” An instructional activity can serve one or many purposes: provide experience with new content or an opportunity to apply mathematics; introduce a new concept and associated language or a new representation; identify and resolve common mistakes; etc. The lesson synthesis “assists the teacher with ways to help students incorporate new insights gained during the activities into their big-picture understanding.” Cool-downs serve “as a brief formative assessment to determine whether students understood the lesson.”

• Resources, Course Guide, How to Use the Materials, “The story of each grade is told in eight or nine units. Each unit has a narrative that describes the mathematical work that will unfold in that unit. Each lesson in the unit also has a narrative. Lesson narratives explain: the mathematical content of the lesson and its place in the learning sequence; the meaning of any new terms introduced in the lesson; how the mathematical practices come into play, as appropriate. Activities within lessons also have narratives, which explain: the mathematical purpose of the activity and its place in the learning sequence, what students are doing during the activity, what the teacher needs to look for while students are working on an activity to orchestrate an effective synthesis, connections to the mathematical practices, when appropriate.”

• Resources, Course Guide, Scope and Sequence lists each of the eight units, a Pacing Guide to plan instruction, and Dependency Diagrams. These Dependency Diagrams show the interconnectedness between lessons and units within Grade 1 and across all grades.

• Resources, Course Guide, Course Glossary provides a visual glossary for teachers that includes both definitions and illustrations. Some images use examples and nonexamples, and all have citations referencing what unit and lesson the definition is from.

Materials include sufficient and useful annotations and suggestions that are presented within the context of the specific learning objectives. Several components focus specifically on the content of the lesson. Examples include:

• Unit 3, Adding and Subtracting Within 20, Overview, describes how subtraction correlates with addition. “Subtraction work occurs throughout the unit and becomes the focus in the last section. Students consider taking away and counting on as methods for subtracting. They understand subtraction as an unknown-addend problem and use their knowledge of addition to find the difference of two numbers.”

• Unit 4, Numbers to 99, Section C, Lesson 14, Activity 1, Launch, provides prompts for the teacher to start the lesson. “Groups of 2: Give each group two paper clips and access to connecting cubes in towers of 10 and singles. Display 35 and 52. “Which number is more? Show your thinking using math tools. Be ready to explain your thinking to your partner.” 2 minutes: independent work time 2 minutes: partner discussion “Which is more and how do you know?” (53 is more because it has more tens than 35.)”

• Unit 8, Putting It All Together, Lesson 6, Activity 1, "The purpose of this activity is for students to practice solving Compare, Difference Unknown story problems (MP2). In the synthesis, students revisit a representation of a Compare problem that was introduced in a previous unit. This representation lays the foundation for working with tape diagrams in grade 2.The teacher may want to incorporate movement into this activity by writing each problem on a piece of chart paper and placing each one in a different location around the classroom. Students can solve the problem at one location, discuss the problem with their partner, then move on to a new problem at a new location."

The materials reviewed for Open Up Resources K-5 Math Grade 1 meet expectations for containing adult-level explanations and examples of the more complex grade-level concepts and concepts beyond the current grade so that teachers can improve their own knowledge of the subject. 

Unit Overviews and sections within lessons include adult-level explanations and examples of the more complex grade-level concepts. Within the Course Guide, How to Use the Materials states, “Activities within lessons also have narratives, which explain: the mathematical purpose of the activity and its place in the learning sequence, what students are doing during the activity, what the teacher needs to look for while students are working on an activity to orchestrate an effective synthesis, connections to the mathematical practices, when appropriate.” Examples include:

• Unit 1, Adding, Subtracting, and Working With Data, Section B, Lesson 7, Activity 1, “The purpose of this activity is for students to sort math tools, name the groups they used to sort, and tell the number of objects in each group. Students identify attributes of the objects and sort them into two or more groups. Students may choose to use one of the blackline masters to organize as they sort. When students share how they sorted with their partner, they use their own mathematical vocabulary and listen to and understand their partner’s thinking (MP3, MP6). Students may describe the objects’ attributes by referring to shape names, number of sides, color, or other attributes. Encourage students to tell how many tools are in each category. During the synthesis, students are introduced to the term category. They discuss different categories that were used to sort the math tools.”

• Unit 5, Adding Within 100, Section B, Lesson 6, Activity 2, “The purpose of this activity is for students to add one-digit and two-digit numbers with composing a ten and deepen their understanding of place value. In this activity, students make sense of two different addition methods where an addend is decomposed to make a ten. Students then determine the next step needed to find the value of the original sum. Invite students to use different representations to make sense of these methods including connecting cubes and base-ten drawings. Completing the start of a calculation as students do here requires critically analyzing, understanding, and expressing different strategies (MP3).”

• Unit 6, Length Measurements Within 120 Units, Section A, Lesson 1, Lesson Narrative, “In kindergarten, students compared the length of two objects directly by lining up the endpoints. They described the objects using language such as longer and shorter. In this unit the words “longer than” and “shorter than” are encouraged, although students may use “taller than” in certain contexts related to height. In this lesson, students compare the length of objects and consider how they know which is longer or shorter. Then, they order three objects by length.”

Also within the Course Guide, About These Materials, Further Reading states, “The curriculum team at Open Up Resources has curated some articles that contain adult-level explanations and examples of where concepts lead beyond the indicated grade level. These are recommendations that can be used as resources for study to renew and fortify the knowledge of elementary mathematics teachers and other educators.” Examples include:

• Resources, Course Guide, About These Materials, Further Reading, K-2, “Units, a Unifying Idea in Measurement, Fractions, and Base Ten. In this blog post, Zimba illustrates how units ‘make the uncountable countable’ and discusses how the foundation built in K-2 measurement and geometry around structuring space allows for the development of fractional units and beyond to irrational units.”

• Resources, Course Guide, About These Materials, Further Reading, Entire Series, “The Number Line: Unifying the Evolving Definition of Number in K-12 Mathematics. In this article, the authors (Lahme, McLeman, Nakamaye, and Umland) focus their attention on the selection of definitions, notation, and graphical conventions surrounding the development of the real numbers from kindergarten to grade 12, and address the work that students might do in later years.”

The materials reviewed for Open Up Resources K-5 Mathematics Grade 1 meet expectations for including standards correlation information that explains the role of the standards in the context of the overall series. 

 Correlation information can be found within different sections of the Course Guide and within the Standards section of each lesson. Examples include:

• Resources, Course Guide, About These Materials, CCSS Progressions Documents, “The Progressions for the Common Core State Standards describe the progression of a topic across grade levels, note key connections among standards, and discuss challenging mathematical concepts. This table provides a mapping of the particular progressions documents that align with each unit in the K–5 materials for further reading.”

• Resources, Course Guide, How to Use the Materials, Noticing and Assessing Student Progress in the Mathematical Practices, The Standards for Mathematical Practices Chart, “The unit-level Mathematical Practice chart is meant to highlight a handful of lessons in each unit that showcase certain Mathematical Practices. Some units, due to their size or the nature of their content, may have fewer predicted chances for students to engage in a particular Mathematical Practice. A dash in the chart indicates that there may not be enough opportunities to reliably look for this Mathematical Practice in the unit. One primary place Mathematical Practice 4 is tagged is the optional modeling lesson at the end of each unit. Aside from these lessons, optional activities and lessons are not included in this chart.”

• Resources, Course Guide, Scope and Sequence, Dependency Diagrams, All Grades Unit Dependency Diagram identifies connections between the units in grades K-5. Additionally, a “Section Dependency Diagram” identifies specific connections within the grade level.

• Resources, Course Guide, Lesson and Standards, provides two tables: a Standards by Lesson table, and a Lessons by Standard table. Teachers can utilize these tables to identify standard/lesson alignment.

• Unit 1, Adding, Subtracting, and Working With Data, Section B, Lesson 8, Standards, “Building On: K.CC.B.4, Addressing: 1.MD.C.4 Organize, represent, and interpret data with up to three categories; ask and answer questions about the total number of data points, how many in each category, and how many more or less are in one category than in another. Building Towards: 1.MD.C.4.”

Explanations of the role of specific grade-level mathematics can be found within different sections of the Resources, Course Guide, Unit Overviews, Section Overviews, and Lesson Narratives. Examples include:

• Resources, Course Guide, Scope and Sequence, each Unit provides Unit Learning Goals, for example, “Students add and subtract within 10, and represent and interpret categorical data.” Additionally, each Unit Section provides Section Learning Goals, “organize and represent data.”

• Unit 2, Addition and Subtraction Story Problems, Overview, “In kindergarten, students solved a limited number of types of story problems within 10 (Add To/Take From, Result Unknown, and Put Together/Take Apart, Total Unknown, and Both Addends Unknown). They represented their thinking using objects, fingers, mental images, and drawings. Students saw equations and may have used them to represent their thinking, but were not required to do so. Here, students encounter most of the problem types introduced in grade 1: Add to/Take From, Change Unknown, Put Together/Take Apart, Unknowns in All Positions, and Compare, Difference Unknown. The numbers are kept within 10 so students can focus on interpreting each problem and the relationship between counting and addition and subtraction. This also allows students to continue developing fluency with addition and subtraction within 10.”

• Unit 4, Numbers to 99, Section D, Section D Overview, "In this section, students deepen their understanding of the base-ten structure by representing two-digit numbers with different amounts of tens and ones. They also extend their comparison work by comparing numbers expressed in different ways."

• Unit 6, Length Measurements Within 120 Units, Section C, Lesson 14, Lesson Narrative, "In previous lessons, students solved Take From, Start Unknown, Compare, Bigger Unknown, and Compare, Smaller Unknown problems. They showed their thinking using drawings, numbers, or words. Throughout the year, students solved all types of story problems with unknowns in all positions. In this lesson, students learn that they can use equations to make sense of story problems in different ways."

The materials reviewed for Open Up Resources K-5 Math Grade 1 meet expectations for providing explanations of the instructional approaches of the program and identification of the research-based strategies. 

The materials explain and provide examples of instructional approaches of the program and include and reference research-based strategies. Both the instructional approaches and the research-based strategies are included in the Course Guide under the Resources tab for each unit. Design Principles describe that, “It is our intent to create a problem-based curriculum that fosters the development of mathematics learning communities in classrooms, gives students access to mathematics through a coherent progression, and provides teachers the opportunity to deepen their knowledge of mathematics, student thinking, and their own teaching practice.” Examples include:

• Resources, Course Guide, Design Principles, “In order to design curriculum and professional learning materials that support student and teacher learning, we need to be explicit about the principles that guide our understanding of mathematics teaching and learning. This document outlines how the components of the curriculum are designed to support teaching and learning aligning with this belief.” Principles that guide mathematics teaching and learning include: All Students are Capable Learners of Mathematics, Learning Mathematics by Doing Mathematics, Coherent Progression, Balancing Rigor, Community Building, Instructional Routines, Using the 5 Practices for Orchestrating Productive Discussions, Task Complexity, Purposeful Representations, Teacher Learning Through Curriculum Materials, and Model with Mathematics K-5.

• Resources, Course Guide, Design Principles, Community Building, “Students learn math by doing math both individually and collectively. Community is central to learning and identity development (Vygotsky, 1978) within this collective learning. To support students in developing a productive disposition about mathematics and to help them engage in the mathematical practices, it is important for teachers to start off the school year establishing norms and building a mathematical community. In a mathematical community, all students have the opportunity to express their mathematical ideas and discuss them with others, which encourages collective learning. ‘In culturally responsive pedagogy, the classroom is a critical container for empowering marginalized students. It serves as a space that reflects the values of trust, partnership, and academic mindset that are at its core’ (Hammond, 2015).”

• Resources, Course Guide, Design Principles, Instructional Routines, “Instructional routines provide opportunities for all students to engage and contribute to mathematical conversations. Instructional routines are invitational, promote discourse, and are predictable in nature. They are ‘enacted in classrooms to structure the relationship between the teacher and the students around content in ways that consistently maintain high expectations of student learning while adapting to the contingencies of particular instructional interactions.’ (Kazemi, Franke, & Lampert, 2009)”

• Resources, Course Guide, Key Structures in This Course, Student Journal Prompts, Paragraph 3, “Writing can be a useful catalyst in learning mathematics because it not only supplies students with an opportunity to describe their feelings, thinking, and ideas clearly, but it also serves as a means of communicating with other people (Baxter, Woodward, Olson & Robyns, 2002; Liedke & Sales, 2001; NCTM, 2000).”

The materials reviewed for Open Up Resources K-5 Math Grade 1 meet expectations for including a comprehensive list of supplies needed to support the instructional activities.

In the Course Guide, Materials, there is a list of materials needed for each unit and each lesson. Lessons that do not have materials are indicated by none; lessons that need materials have a list of all the materials needed. Examples include:

• Resources, Course Guide, Key Structures in This Course, Representations in the Curriculum, provides images and explanations of representations for the grade level. “5-frame and 10-frame (K-2): 5- and 10-frames provide students with a way of seeing the numbers 5 and 10 as units and also combinations that make these units. Because we use a base-ten number system, it is critical for students to have a robust mental representation of the numbers 5 and 10. Students learn that when the frame is full of ten individual counters, we have what we call a ten, and when we cannot fill another full ten, the ‘extra’ counters are ones, supporting a foundational understanding of the base-ten number system. The use of multiple 10-frames supports students in extending the base-ten number system to larger numbers.”

• Resources, Course Guide, Materials, includes a comprehensive list of materials needed for each unit and lesson. The list includes both materials to gather and hyperlinks to documents to copy. “Unit 1, Lesson 13 - Gather: Connecting cubes, Materials from a previous activity; Copy: Favorite Special Class Data.”

• Unit 8, Putting it All Together, Section B, Lesson 5, Materials Needed, “Activities: Connecting cubes in towers of 10 and singles (Activity 1).”

The materials reviewed for Open Up Resources K-5 Math Grade 1 meet expectations for providing strategies and supports for students in special populations to support their regular and active participation in learning grade-level/series mathematics.

Materials regularly provide strategies, supports, and resources for students in special populations to help them access grade-level mathematics as suggestions are outlined within each lesson. According to the Resources, Course Guide, Universal Design for Learning and Access for Students with Disabilities, “Supplemental instructional strategies that can be used to increase access, reduce barriers and maximize learning are included in each lesson, listed in the activity narratives under ‘Access for Students with Disabilities.’ Each support is aligned to the Universal Design for Learning Guidelines (udlguidelines.cast.org), and based on one of the three principles of UDL, to provide alternative means of engagement, representation, or action and expression. These supports provide teachers with additional ways to adjust the learning environment so that students can access activities, engage in content, and communicate their understanding.” Examples of supports for special populations include: 

• Unit 4, Numbers to 99, Section D, Lesson 19, Activity 2, Access for Students with Disabilities, “Action and Expression: Executive Functions. Invite students to plan a method with their partners, including the tools they will use, for decomposing 37 in multiple ways. Provides accessibility for: Organization, Attention”

• Unit 7, Geometry and Time, Section A, Lesson 5, Access for Students with Disabilities, “Representation: Comprehension. Synthesis: Provide more examples and non-examples to reinforce the defining attributes of triangles. Provides accessibility for: Conceptual Processing, Visual-Spatial Processing”

• Unit 8, Putting It All Together, Section B, Lesson 4, Activity 1, Access for Students with Disabilities, “Representation: Perception. Provide appropriate reading accommodations and supports to ensure student access to word problems and other text-based content. Provides accessibility for: Language, Visual-Spatial Processing, Attention.”

The materials reviewed for Open Up Resources K-5 Math Grade 1 meet expectations for providing extensions and/or opportunities for students to engage with grade-level/course-level mathematics at higher levels of complexity.

While there are no instances where advanced students do more assignments than classmates, materials do provide multiple opportunities for students to investigate grade-level content at a higher level of complexity. These are found where problems are labeled as “Exploration” at the end of practice problem sets within sections, where appropriate. According to the Resources, Course Guide, How To Use The Materials, Exploration Problems, “Each practice problem set also includes exploration questions that provide an opportunity for differentiation for students ready for more of a challenge. There are two types of exploration questions. One type is a hands-on activity directly related to the material of the unit that students can do either in class if they have free time, or at home. The second type of exploration is more open-ended and challenging. These problems go deeper into grade-level mathematics. They are not routine or procedural, and they are not just “the same thing again but with harder numbers. Exploration questions are intended to be used on an opt-in basis by students if they finish a main class activity early or want to do more mathematics on their own. It is not expected that an entire class engages in exploration problems, and it is not expected that any student works on all of them. Exploration problems may also be good fodder for a Problem of the Week or similar structure.” Examples include:

• Unit 1, Adding Subtracting, and Working With Data, Section A, Practice Problems, Problem 10 (Exploration), “Materials needed: Number cards 2–10; Two dot cubes. Directions: a. Choose a number card. Show 2 numbers on the dot cubes that add to make your number. b. Can you show another way?”

• Unit 3, Adding and Subtracting Within 20, Section D, Practice Problems, Problem 6 (Exploration), “Mai was playing Number Card Subtraction. She started with a teen number. Then she drew a card and subtracted. Mai’s answer was the same as the number she subtracted. What could Mai’s teen number and card have been?”

• Unit 6, Length Measurements within 120 Units, Section B, Practice Problems, Problem 6 (Exploration), “Priya and Noah want to measure their classroom in steps. Priya takes 28 steps to cross the room and Noah takes 26 steps. a. How could Priya and Noah get different measurements?; b. Measure the length of your classroom in steps.”

The materials reviewed for Open Up Resources K-5 Math Grade 1 meet expectations for providing strategies and supports for students who read, write, and/or speak in a language other than English to regularly participate in learning grade-level mathematics.

Guidance is consistently provided to teachers to support students who read, write, and/or speak in a language other than English, providing scaffolds for them to meet or exceed grade-level standards. According to the Resources, Course Guide, Mathematical Language Development and Access for English Learners, “In an effort to advance the mathematics and language learning of all students, the materials purposefully engage students in sense-making and using language to negotiate meaning with their peers. To support students who are learning English in their development of language, this curriculum includes instruction devoted to fostering language development alongside mathematics learning, fostering language-rich environments where there is space for all students to participate.” Examples include:

• Unit 1, Adding, Subtracting, and Working With Data, Section C, Lesson 11, Activity 1, “Access for English Learners - Reading, Representing: MLR6 Three Reads. To launch this activity, display the task statement. ‘We are going to read this statement 3 times.’ After the 1st Read, ask: ‘What is this situation about?’ Listen for and clarify any questions about the context. After the 2nd Read: ‘What are all the things we can count?’ (number of votes for each pet, number of classmates who took the survey). After the 3rd Read: ‘How can we know if a statement is true or false?’”

• Unit 2, Addition and Subtraction Story Problems, Section A, Lesson 3, Activity 1, "Access for English Learners - Representing, Conversing: MLR7 Compare and Connect. Synthesis: After all methods have been presented, lead a discussion comparing, contrasting, and connecting the different approaches. Ask, ‘How were the different methods the same?’ and ‘How were they different?’”

• Unit 4, Numbers to 99, Lesson 1, Activity 1, Access for English Learners, "Conversing, Reading: MLR2 Collect and Display. Circulate, listen for, and collect the language students use as they work with their partners. On a visible display, record words and phrases such as: count, represent, representation, my representation shows … Invite students to borrow language from the display as needed, and update it throughout the lesson."

The materials reviewed for Open Up Resources K-5 Math Grade 1 meet expectations for providing manipulatives, both virtual and physical, that are accurate representations of the mathematical objects they represent and, when appropriate, are connected to written methods.

Suggestions and/or links to manipulatives are consistently included within materials to support the understanding of grade-level math concepts. Examples include:

• Unit 1, Adding, Subtracting, and Working With Data, Section A, Lesson 4, Activity 1, students use number cards, a game board, two-color counters, and access to 10-frames to subtract one or two from a number within 10. Launch, “Groups of 2. ‘We are going to learn a new way to play, Five in a Row. Last time we played, we added one or two to the number on our card. This time, you will take turns flipping over a card and choosing whether to subtract one or two from the number. Then put a counter on the number on the game board, The first person to get five counters in a row wins. Remember, your counters can be in a row across, up and down, or diagonally.’” Student Work Time, “10 minutes: partner work time. As students work, consider asking: ‘How did your subtract? How did you decide whether to subtract 1 or 2?’”

• Unit 4, Numbers to 99, Section A, Lesson 4, Activity 1, “The purpose of this activity is for students to solve two story problems involving adding or subtracting multiples of 10. Students are presented with a familiar context from a previous lesson in which students counted cubes in different bags. The quantities of cubes are described using representations that students are familiar with, and students add or subtract in a way that makes sense to them. The familiar context and representations are used to help students make sense of adding and subtracting tens. In the synthesis, students compare and connect the different representations used for each problem (MP2).”

• Unit 6, Length Measurements Within 120 Units, Section B, Lesson 3, Activity 1, “Students choose from a variety of objects: connecting cubes towers, pieces of string, and unsharpened pencils. As students compare the length of the paths, students may use a single tool, such as a piece of string to compare the two paths. They may mark or cut the string. Some students may choose the tower of connecting cubes and determine that breaking off or counting the cubes is a way to determine whether one length is shorter or longer than the other. Others may select and try different tools until they find one that has a length that is in between the length of the two paths.”