GRADE 2 | MODULE 1 | TOPIC A | LESSONS 1–2 KEY CONCEPT OVERVIEW During the next few days, our math class will be reviewing and building upon familiar skills established in Grades K and 1. We will be working toward the Grade 2 goal of fluently adding and subtracting numbers up to 100. You can expect to see homework that asks your child to do the following: ■■ Use a number bond to show a total and two parts for numbers 6–10. For example, if 9 is the total and 7 is one part, then 2 is the other part. ■■ Recall partners to ten (e.g., 1 and 9, 2 and 8, 3 and 7). ■■ Recall ten plus facts (e.g., 10 + 3 = 13; 10 + 7 = 17). ■■ Add single-digit numbers to a multiple of ten to reach a given total; for example, 80 + = 82. SAMPLE PROBLEM (From Lesson 1) Add or subtract. Then complete the number bond to match. 10 = 4 + 6 10 = 6 + 4 10 – 6 = 4 10 – 4 = 6 Additional sample problems with detailed answer steps are found in the Eureka Math Homework Helpers books. Learn more at GreatMinds.org. For more resources, visit » Eureka.support GRADE 2 | MODULE 1 | TOPIC A | LESSONS 1–2 HOW YOU CAN HELP AT HOME ■■ If your child would benefit from using concrete objects for support, provide pennies (or other counters) to help him break apart numbers into two parts. The use of fingers is also encouraged! ■■ Encourage your child to explain how she knows the correct answer. For example, “I know that 10 – 7 = 3, so that means 10 – 3 = 7. Three and seven are parts and 10 is the total.” ■■ Practice counting the Say Ten way. Say a two-digit number (e.g., 23 or 37), and ask your child to repeat it the Say Ten way (2 tens 3; 3 tens 7). For fun, invite your child to say some numbers for you to repeat the Say Ten way. TERMS Say Ten counting: An East Asian method of counting that reinforces place value understanding by asking students to break two-digit numbers into tens and ones. In Grade 2, Say Ten counting extends to numbers in the hundreds. For example, 573 becomes “5 hundreds 7 tens 3.” Part: One of two (or more) numbers that add up to a given total. For example, in 3 + 5 = 8, the parts are 3 and 5. Partners to ten: Pairs of numbers that add up to ten: 1 and 9, 2 and 8, 3 and 7, and so on. Ten plus facts: Ten plus ____ one(s) makes a teen number (11–19); for example, 10 + 1 = 11, 10 + 2 = 12, and so on. MODELS Number Bond: A model that shows the relationship between a number (whole) and its parts. (whole) (part) (part) For more resources, visit » Eureka.support © 2016, GREAT MINDS® GRADE 2 | MODULE 1 | TOPIC B | LESSONS 3–8 KEY CONCEPT OVERVIEW During the next two weeks, our math class will be adding and subtracting numbers to 100, building upon Grade 1 skills at a quickened pace, and using strategies to make problems easier. You can expect to see homework that asks your child to do the following: ■■ Add and subtract like units. (e.g., in 73 – 21, 7 tens – 2 tens = 5 tens, and 3 ones – 1 one = 2 ones.) ■■ Use a number bond to make a ten when adding numbers up to 100; for example, 38 + 7 can be thought of as 38 + 2 + 5, and from there, we can make the simpler problem, 40 + 5. ■■ Use a number bond to take from ten when subtracting numbers up to 100; for example, 67 – 9 can be thought of as 57 + 10 – 9, and from there, we can make the simpler problem, 57 + 1. SAMPLE PROBLEM (From Lessons 4, 5, 7, 8) Mary buys 30 stickers. She uses 7 stickers. How many stickers does Mary have left? Solution 1: Solution 2: 30 – 7 = 23 7 + 23 = 30 Mary has 23 stickers left. Additional sample problems with detailed answer steps are found in the Eureka Math Homework Helpers books. Learn more at GreatMinds.org. For more resources, visit » Eureka.support GRADE 2 | MODULE 1 | TOPIC B | LESSONS 3–8 HOW YOU CAN HELP AT HOME ■■ Encourage your child to explain one strategy he can use to solve a problem. For example, “I know that 61 + 20 = 81 because 20 is two tens. I started with 61 and I counted on two tens: 61, 71, 81.” ■■ Play “Make the Next Ten”: Partner A calls out a number (e.g., 28). Partner B tells how many ones are needed to make the next ten, and then says the number sentence (2; 28 + 2 = 30). ■■ Play “Take out a Ten”: Partner A calls out a number (e.g., 67). Partner B takes out a ten, states the remaining part (57), and provides a related number sentence (67 - 10 = 57, or 57 + 10 = 67). TERMS Make a ten: An addition strategy used to make a unit of ten. For example, 39 + 4 can be thought of as 39 + 1 + 3, and from there, we can make the simpler problem, 40 + 3. Take from ten: A strategy used to subtract from a unit of ten. For example, 30 – 9 can be thought of as 20 + 10 – 9, and from there, we can make the simpler problem, 20 + 1. RDW process: A 3-step problem-solving method that requires students to 1) Read the problem, 2) Draw a picture, and 3) Write an equation and statement of the answer. Students may draw a tape diagram as part of Step 2. (See Sample Problem and Solution 2 above.) MODELS Number Bond: A model that shows the Quick Tens and Ones: A math relationship between a number (whole) and drawing used to represent tens and its parts. ones. A vertical line represents each ten; dots represent ones. For example, (whole) 27 = 2 tens 7 ones. (part) (part) For more resources, visit » Eureka.support © 2016, GREAT MINDS® GRADE 2 | MODULE 2 | TOPIC A | LESSONS 1–3 KEY CONCEPT OVERVIEW During the next three days, our math class will be learning concepts about measuring in centimeters. We will learn how to measure, first by using centimeter cubes, next by using one cube with the mark and move forward technique, and finally by creating centimeter rulers in class. You can expect to see homework that asks your child to do the following: ■■ Measure pictures of objects by counting centimeter squares (a flat, two-dimensional version of the centimeter cube used in class). ■■ Measure pictures of objects using the mark and move forward technique. ■■ Measure pictures of objects using a student-made centimeter ruler, then compare lengths of objects. SAMPLE PROBLEM (From Lesson 2) Use the centimeter square provided to measure the length of the calculator. Mark the endpoint of the square as you measure. The picture of the calculator is about 6 cm long. Additional sample problems with detailed answer steps are found in the Eureka Math Homework Helpers books. Learn more at GreatMinds.org. For more resources, visit » Eureka.support GRADE 2 | MODULE 2 | TOPIC A | LESSONS 1–3 HOW YOU CAN HELP AT HOME ■■ Our class will not use rulers until Lesson 3 of this module. Until the class completes Lesson 3, invite your child to practice measuring with the centimeter square. Please do not provide a store-bought ruler. ■■ Remember that measurements made with little fingers may not be perfect. Encourage your child to do her best and focus on the process of measuring rather than on finding an exact measurement. ■■ Continue to reinforce these strategies from Module 1. Make the Next Ten: Say a number less than 100 (e.g., 47). Invite your child to tell how many more are needed to make the next ten (3). Make Ten: When solving addition problems to 20, encourage your child to “make ten” to help add the numbers. For example, 9 + 3 = 10 + 2. TERMS Mark and move forward: A strategy used to avoid overlap when measuring with a tool such as a centimeter cube. For example, “I place my cube down and make a mark right where it ends. Then I lift my cube and put it down again, making sure my cube is right against the line, and make another mark. I keep going until I reach the end of the object.” Endpoint: The point where something begins or ends. Hash marks: The marks on a ruler or other measurement tool. For more resources, visit » Eureka.support © 2016, GREAT MINDS® GRADE 2 | MODULE 2 | TOPIC B | LESSONS 4–5 KEY CONCEPT OVERVIEW During the next few days, students will build on what they learned in Topic A as they continue learning about measurement. We will learn to use different tools (centimeter rulers, meter tapes, and meter sticks) to measure various objects in our classroom. Then, we will learn to estimate length using mental benchmarks. You can expect to see homework that asks your child to do the following: ■■ Choose the correct unit—centimeters or meters—for measuring an object. ■■ Measure objects using a centimeter ruler. ■■ Estimate the lengths of various objects, using mental benchmarks. For example, a centimeter is about the width of a pinky finger. SAMPLE PROBLEM (From Lesson 5) Circle the best estimate for each object. a. length of a push pin b. length of a classroom door c. length of a pair of scissors Additional sample problems with detailed answer steps are found in the Eureka Math Homework Helpers books. Learn more at GreatMinds.org.