For the student For the teacher

Teacher Edition

Math on the Spot Video Tutor Online Assessment

System

Soar to Success Math Online Intervention

iTools Virtual Manipulatives

Digital ManagementCenter organizes program resources by TEKS!

Interactive Student Edition provides students

with an interactive learning environment!

Resources

e

How do you record the steps when adding 2-digit

numbers?

Lesson OpenerMaking ConnectionsInvite children to talk about American football.

Do you know anyone who plays football? (Answers will vary.) Do you have a favorite team? (Answers will vary.) How many points do you get for scoring a touchdown in football? (6 points) How many points do you get for scoring a field goal? (3 points for a field goal)

Using the Digital LessonYou can use the digital lesson opener as a whole-class activity. You can pause at any point to have a discussion. Children will have the opportunity to return to the opening scenario and answer the question in the first Daily Assessment Task. You may want to discuss the different ways the teams could have earned their points. (Team one, 3 touchdowns, each with an extra point, and 2 field goals; Team two, 2 touchdowns, each with an extra point, and 1 field goal)

Learning TaskEncourage discussion about the facts given.

• How many points did Team one score? (27)

• How many points did Team two score? (17)

• What number is in the tens place for Team one’s score? (2) Ones place? (7)

• What number is in the tens place for Team two’s score? (1) Ones place? (7)

Literacy and MathematicsView the lesson opener with the children. Then, choose one or both of the following activities.

• Ask children to write a story about a football game and its scores.

• Ask children to write a story using 2-digit addition and solve the problem.

Texas Essential Knowledge and Skills

Number and Operations—2.4.B Add up to four two-digit numbers and subtract two-digit numbers using mental strategies and algorithms based on knowledge of place value and properties of operations

MATHEMATICAL PROCESSES2.1.D Communicate mathematical ideas and reasoning2.1.E Create and use representations

Are You Ready?Access Prior KnowledgeUse the Are You Ready? 7.1 in the Assessment Guide to assess children’sunderstanding of the prerequisite skills for this lesson.

Vocabulary

Go to Multimedia eGlossary at thinkcentral.com

MaterialsMathBoard

7.1 2-Digit Addition How do you record the steps when adding 2-digit numbers?Essential Question?

Lesson 7.1 205A

ExploreHands

OnExploreExplore

Mathematical ProcessesMath Talk

Essential Question?

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Number and Operations—2.4.B

MATHEMATICAL PROCESSES2.1.D, 2.1.E

Name

2-Digit Addition7.1

FOR THE TEACHER • Read the following problem and have children draw quick pictures to solve. The animal shelter has 35 dogs and 47 cats for adoption. How many pets are at the shelter? Repeat the activity with this problem.

After a pet fair, there are only 18 dogs and 21 cats at the shelter. How many pets are at the shelter now?

Explain when you need to regroup

ones.

How do you record the steps when adding 2-digit numbers?

Draw quick pictures to model each problem.

Tens Ones

Check children’s drawings.

The answer is 82 pets.

The answer is 39 pets.

Math Talk: Possible explanation: When there are 10 or more ones in all, I need to regroup 10 ones as 1 ten.

Module 7 two hundred five 205

Language SupportELLEnglish Language LearnersLeveled Activities ELPS

Beginning: Activity 19 1.A.1, 3.G.2, 4.C.3

Intermediate: Activity 21 3.D.2, 3.G.1, 4.D

Advanced: Activity 3 2.I.3, 2.I.5, 4.F.2

Advanced High: Activity 43 4.F.6, 4.G.2, 4.G.4

Go to thinkcentral.com for the ELL Activity Guide containing these leveled activities.

ELPS 3.B.3, 3.C.4, 3.G.2

Strategy: Describe• Children demonstrate their comprehension of addition by describing

what they do to find sums.• Display the addition sentence 49 + 45 = _____ .• Have children describe the steps they

would take to regroup and find the sum. Then have children regroup and write the sum.

• Repeat the activity with 37 + 24 = _____ .

Verbal / LinguisticSmall Group

ExploreAs you read the problem below, write 35 and 47 on the board.

The animal shelter has 35 dogs and 47 cats for adoption. How many pets are at the shelter?

• How do you use quick pictures to help you solve this problem? Possible answer: For 35, I draw 3 tens and 5 ones. For 47, I draw 4 tens and 7 ones. Because there are 12 ones in all, I will regroup 10 ones as 1 ten. Then I will have 8 tens and 2 ones, which is 82.

• How do you show the regrouping in the quick pictures? Possible answer: I put a ring around 10 ones and then draw an arrow from these ones to another ten I draw in the Tens column. That shows that I am regrouping 10 ones as 1 ten.

Have children draw quick pictures in the top box to model the problem.

• How many pets are at the shelter? 82 pets

Repeat for the following problem.

After a pet fair, there are only 18 dogs and 21 cats at the shelter. How many pets are at the shelter now? 39 pets

Have children draw quick pictures in the bottom box to model the problem. Ask them to explain why they do not regroup for this problem.

HandsOn

Math Talk Use Math Talk to focus on children’s understanding of when to regroup ones when adding 2-digit numbers.

Mathematical Processes

1 49 + 45

_

94

205 Module 7

Tens OnesTens OnesTens Ones

Tens Ones Tens Ones Tens Ones

B9

41

3

Tens Ones

1

5

2

8

B5

1 2

Tens Ones

9

4

3

1B5

1 2

Tens Ones

9

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Model and DrawModel and Draw

Share and ShowShare and Show

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Regroup if you need to. Write the sum.

1. 2. 3.

Add 59 and 24.

Step 1 Add the ones.

9 + 4 = 13

Step 2 Regroup. 13 ones is the same as 1 ten 3 ones.

Step 3 Add the tens.

1 + 5 + 2 = 8

B 1B 4 2

+ 2 9

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7 1

3 1

+ 1 4

___

4 5

2 7

+ 4 5

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7 2

1B

206 two hundred six

Enrich Verbal / LinguisticIndividual / Partners

Materials: index cards

• Ask children to write three 2-digit numbers on an index card. Have children exchange cards with a partner.

• Challenge children to write three addition story problems. The sum for each problem should match one of the numbers on the index card.

• Have partners exchange stories and solve.

1

2

3

a child misses the checked exercise(s)

Quick Check

IF

THENDifferentiate Instruction with:RtI Tier 1 Lesson 31

Model and DrawWork through the model with children.

• In Step 2, where do you record the ones after you have regrouped? at the bottom of the Ones column, as part of the sum Where do you record the new ten? at the top of the Tens column

• In Step 3, what does the 8 at the bottom of the Tens column show? the sum of the tens

Share and ShowExercises 1–3 connect to the learning model.

• Look at Exercises 1–3. In which of these exercises will you need to regroup? Explain. Exercises 1 and 3; Possible explanation: There are 10 or more ones in each of these exercises.

Use the checked exercise(s) for Quick Check. Children should use their MathBoards to show their answers to these exercises.

COMMON ERRORSError Children may forget to add the regrouped 10.

Springboard to Learning Ask children to modelthe problem using quick pictures. To reinforce the learning, emphasize that when the 10 ones are regrouped as 1 ten, the 1 should be written above the other tens in the Tens column so that it is not forgotten.

CE

Lila’s team scored 27points. Anna’s team scored46 points. How many pointsdid the teams score in all?

73, 48, 95

Go to Go to thinkcentral.com for additional enrichmentactivities in the Enrich Activity Guide. Lesson 7.1 206

Problem SolvingProblem Solving

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10. Multi-Step Jin has 31 books about cats and 19 books about dogs. He gives 5 books to his sister. How many books does Jin have now?

45 — books

4.

3 3

+ 2 7

___

6 0

1 5.

5 2

+ 5

___

5 7

6.

3 6

+ 5 8

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9 4

1

7.

6 4

+ 2 5

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8 9

8.

3 5

+ 3 8

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7 3

1 9.

3 8

+ 5 2

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9 0

1

11. Abby used a different way to add. Describe Abby’s way of adding 2-digit numbers.

—————

—————

—————————

—————————

35 + 48

_

13 + 70_

83

Regroup if you need to. Write the sum.

Solve. Write or draw to explain.

Possible answer: First, add the ones and

write that sum below the problem. Then

add the tens and write that sum below the

sum of the ones. Finally, find the sum of these two numbers.

Module 7 • Lesson 1 two hundred seven 207

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2.4.B

Add 27 and 36.

Model 27 and 36. Add the ones.7 + 6 = 13

If you can make a 10, regroup 10 ones for 1 ten.13 ones =1 ten 3 ones

Add the tens. Remember to add the regrouped ten.1 + 2 + 3 = 6

Regroup if you need to. Write the sum.

1. 2. 3. 4.

2-Digit AdditionOBJECTIVE Record 2-digit addition using the standard algorithm.

LESSON 31

STEP 1 STEP 2 STEP 3

Tens Ones Tens Ones Tens Ones

B2 7

� 3 6

Tens Ones

B2 73

1

6

3

Tens Ones

+

B2 73

1

6

36

Tens Ones

+

B5 42

1

9

38

Tens Ones

+

B1 76 1

87

Tens Ones

+

B4 12

1

9

07

Tens Ones

+

B3 53 2

76

Tens Ones

+

Number and Operations 61

B1 2

+ 4 9

15

Tens Ones

B1 2

+ 4 9

1

1

6

Tens Ones

B3 7

+ 4 53

1

8

Tens Ones

B3 7

+ 4 5

2

1

8

Tens Ones

B22

6+ 2 6

24

Tens Ones

B2 6

+ 2 6

2

1

5

Tens Ones

B71

2+ 1 9

18

Tens Ones

B7 2

+ 1 91

1

9

Tens Ones

Enrich© Houghton Mifflin Harcourt Publishing Company

E27

Name Enrich 27

Adding ErrorsFind the errors in the addition problems. Circle the errors. Then show how to solve the problems correctly.

1. 2.

3. 4.

Writing and Reasoning Describe the error you found in Exercise 4.

Possible answer: The sum in Exercise 4 is wrong

because the regrouped ten was not added to the

other tens.

1

2

3

Enrich 27RtI Tier 1 Lesson 31

Problem SolvingIf children answer the checked exercise(s) correctly, assign the exercises on this page.

ProblemsThese problems require children to use higher order thinking skills and/or multiple steps to solve the problem.

For Exercise 10, children will need to add to find how many books Jin starts with, then subtract to find the number of books he now has.

For Exercise 11, have pairs discuss Abby’s way. Discuss how this method relates to the method taught previously: breaking apart both addends and then adding in steps.

Go DeeperTo extend children’s thinking, write these problems on the board. Ask children to find and correct the error in each.

1 58

+ 21

_

89

36 + 27

_

513

Ask children to share their reasoning about how they think the error was made.

Math on the Spot Video Tutor

Through the Math on the Spot Video Tutor, children will be guided through an interactive solving of this type of H.O.T. problem. Use this video to also help children solve the H.O.T. problem in the Interactive Student Edition. With these videos and H.O.T. problems, children will build skills needed in the TEXAS assessment.

MV

Math on the Spot videos are in theInteractive Student Edition and atthinkcentral.com.

207 Module 7

Daily Assessment TaskDaily Assessment Task

Mathematical Processes

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Choose the correct answer.

12. Connect A shark grew 18 new teeth in one week. It grew 17 more new teeth the next week. How many new teeth did the shark grow in two weeks?

35

28

37

13. A shark swam 48 miles on Monday. On Tuesday, the shark swam another 48 miles. How many miles did the shark swim in all on these two days?

48

96

86

14. Reasoning Anna has 31 animal cards. Roy has 49 animal cards. How many animal cards do the two children have?

79

70

80

15. TEXAS Test Prep Carlos had 68 stamps in his collection. He bought 14 more stamps. How many stamps does he have now?

TAKE HOME ACTIVITY • Ask your child to show you two ways to add 45 and 38.

74

82

56

208 two hundred eight

Games

THENIF

YES

NO

Daily Assessment Task 1

2

3

Differentiated Centers Kit

ActivitiesMarbelousChildren complete blue Activity Card 9 by reviewing 2-digit addition with regrouping.

LiteratureButterfly FarmChildren read about adding the number of butterflies Abby and Nat see.

GamesSoccer SumsChildren add 2-digit numbers to score a goal.

TEXAS Test Prep CoachTest Prep Coach helps teachers to identify common errors that children can make.

If children selected:

• 74, they subtracted the ones and added the tens.

• 56, they subtracted incorrectly.

Essential Question? WriteMathWriteMath

How do you record the steps when adding 2-digit numbers? Possible answer: First I add the ones. If there are 10 or more ones, I regroup 10 ones as 1 ten, record the regrouped ten, and record the remaining ones in the sum. Then I add the tens and record the tens digit in the sum.

• Enrich 27

• Homework and Practice Lesson 7.1

• Soar to Success MathWarm-Up 10.34

Can children use the standard algorithm to record 2-digit addition?

Lesson 7.1 208

Lesson CheckLesson CheckTEXAS Test Prep

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Choose the correct answer.

8. Olivia had 48 shells. She found 16 more shells at the beach. How many shells does she have now?

62

64

54

9. Mr. Jordan walked 22 miles during one week. The next week he walked another 22 miles. How many miles did Mr. Jordan walk in all?

44 miles

22 miles

46 miles

10. Kelly has 25 ribbons for swimming. Todd has 35 ribbons for swimming. How many ribbons do the two friends have together?

55

70

60

11. Multi-Step Marie counts 14 turtles at the pond. Scott counts double that number of fish in the pond. How many turtles and fish did they see at the pond?

32

42

28

210 two hundred ten

Tens Ones

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Homeworkand Practice

2-Digit Addition

Number and Operations—2.4.BMATHEMATICAL PROCESSES 2.1.D, 2.1.E

7.1Regroup if you need to. Write the sum.

1. 2. 3.

4. 5. 6.

B

B

1

11

B

B

4 6 + 2 4

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7 0

6 3 + 1 8

___

8 1

5 3 + 6

___

5 9

2 5 + 4 8

___

7 3

3 3 + 3 9

___

7 2

4 4 + 4 7

___

9 1

1

1

B

B

7. Keith has 22 sun stickers and 28 star stickers. How many stickers does Keith have now?

Solve. Write or draw to explain.

50 — stickers

Problem SolvingProblem Solving

Module 7 two hundred nine 209

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Homework and PracticeUse the Homework and Practice pages to provide children with more practice on the concepts and skills of this lesson.

209-210 Module 7