## enVision Math Common Core 2nd Grade Answers Key Topic 3 Add Within 100 Using Strategies

**Essential Question:**

What are strategies for adding numbers to 100?

**enVision STEM Project: Earth Changes and Addition Strategies**

Find Out Find and share books about how the Earth changes. Talk about changes that people can see, hear, and feel. Talk about changes that people cannot see happening.

Journal: Make a Book Show what you learn in a book. In your book, also:

- Write new science words you learn. Draw pictures that help show what the words mean.
- Write new math words you learn. Draw pictures that help show what the words mean.

**Review What You Know**

**Vocabulary**

Question 1.

Draw a circle around each even number. Use cubes to help.

15

7

14

2

19

18

Answer:

In the given numbers 14, 2 and 18 are the even numbers.know draw a circle around the 14, 2 and 18.

Question 2.

Draw a square around each odd number. Use cubes to help.

12

3

6

17

11

4

Answer:

In the given numbers 3,17 and 11 are the odd numbers. Know draw the square around the 3, 17 and 11.

Question 3.

Complete the bar diagram to show the sum of 3 + 5.

Answer:

In the above diagram they have given a 3 dots on the left side. Know we want to draw 5 dots on the right side. By adding both sides of the dots wet get 3 + 5 = 8

Arrays

Write an equation to show the number of circles in each array.

Question 4.

By rows

_______ + _______ = _______

Answer:

Given,

Total number of rows = 2

Each row contains 4 circles.

4 + 4 = 8

Question 5.

By columns

_______ + _______ = _______

Answer:

Given that,

Total number of columns = 3

Each column contains 3 circles.

3 + 3 + 3 = 9

**Math Story**

Question 6.

Joe has 5 apples. He picks 3 more apples. How many apples does Joe have now?

_______ apples

Does Joe have an even or an odd number of apples?

_________ number

Answer:

Given that

Total number of apples at Joe = 5

Joe picks more apples = 3

Total number of apples near Joe = 5 + 3 =8

Joe has an even number of apples.

**Pick a Project**

PROJECT ЗА

How far would you travel to cheer for your team?

Project: Make a Map to the Game

PROJECT ЗB

What are some important things to do at the airport?

Project: Write a List of Air Travel Tasks

PROJECT 3C

How many Olympic Games have there been?

Project: Create an Olympics Poster

**3-ACT MATH PREVIEW**

Math Modeling

Piled Up

### Lesson 3.1 Add Tens and Ones on a Hundred Chart

**Solve & Share**

How can you use the hundred chart to help you find 32 + 43? Explain.

Write an equation to show the sum.

I can … add within 100 using place-value strategies and properties of operations.

______ + _______ = ________

Visual Learning Bridge

Convince Me! Max says that to find 54 + 18 on a hundred chart, you can start at 54, move down 2 rows, and move back 2 spaces. Do you agree? Explain.

**Guided Practice**

Add using the hundred chart. Draw arrows on the chart if needed.

Question 1.

17 + 32 = ________

Answer:

We are using the hundred chart to find the sum of 17 + 32

In the hundred charts we start at 17 moves down to 3 rows and move front to 2 spaces then we get 49

17 + 32 = 49

Question 2.

28 + 21 = ________

Answer:

We are using the hundred chart to find the sum of 28 + 21

In the hundred charts we start at 28 move down to 2 rows and move front to 1 space then we get 49.

28 + 21 = 49

Question 3.

________ = 19 + 20

Answer: we are using a hundred charts to find the sum of 19 + 20

In the hundred charts we start at 19 moves down to 2 rows then we get 39.

39 = 19 + 20

Question 4.

18 + 8 = ________

Answer:

We are using the hundred chart to find the sum of 18 + 8

In the hundred charts, we start at 18 moves down to 1 row and back to 2 space then we get 26

18 + 8 = 26

**Independent Practice**

Add using the hundred chart.

Question 5.

33 + 9 = ________

Answer:

We are using the hundred chart to find the sum of 33 + 9

In the hundred charts we start at 33 down to 1 row and move back to 1 space then we get 42

33 + 9 = 42

Question 6.

________ = 12 + 73

Answer:

We are using the hundred chart to find the sum of 12 + 73

In the hundred charts we start at 12 down to 7 rows and move front to 3 Space we get 85

85 = 12 + 73

Question 7.

38 + 21 = ________

Answer:

We are using the hundred chart to find the sum of 38 + 21

In the hundred charts we start at 38 down to 2 rows and front to 1 space then we get 59

38 + 21 = 59

Question 8.

56 + 42 = ________

Answer:

We are using the hundred chart to find the sum of 56 + 42

In the hundred charts we start at 56 down to 4 rows and front to 2 spaces then we get 98

56 + 42 = 98

Question 9.

________ = 47 + 28

Answer:

We are using the hundred chart to find the sum of 47 + 28

In the hundred charts, we start at 47 down to 3 rows and back to 2 spaces then we get 75

75 = 47 + 28

Question 10.

39 + 17 = ________

Answer:

We are using the hundred chart to find the sum of 39 + 17

In the hundred charts, we start at 39 down to 2 rows and back to 3 spaces then we get 56

39 + 17 =56

Question 11.

________ = 61 + 19

Answer:

We are using the hundred chart to find the sum of 61 + 19

In the hundred charts, we start at 61 and down to 2 rows and back to 8 space then we get 89

89 = 61 + 19

Question 12.

**Higher Order Thinking** Write the digit that makes each equation true.

Answer:

7 + 83 = 90

The number 7 makes the equation true.

34 + 25 = 57

The digit 5 makes the equation true.

16 + 52 = 67

The digit 1 makes the equation true.

62 + 21 = 83

The digit 2 makes the equation true.

**Problem Solving**

Use Tools Use the hundred chart to solve the problems.

Question 13.

Sara has 48 buttons. Luis has 32 buttons. How many buttons do they have in all?

________ buttons

Answer:

Given that,

Total number of buttons at Sara = 48

Total number buttons at Luis = 32

The total number of buttons at both of them have = 48 + 32

By using a hundred charts the sum of 48 + 32 is

In the hundred charts Start at 48 and down to 3 rows and front to 2 spaces then we get 80.

48 + 32 = 80

Question 14.

Mika had 70 buttons. Then she found 19 more buttons. How many buttons does Mika have now?

_______ buttons

Answer:

Given that,

Total number of buttons at Mika = 70

She found more buttons = 19

Total number of buttons with Mike = 70 + 19

By using the hundred chart we find the sum of 70 + 19

In the hundred chart, we start at 70 then down to 2 rows and back to 1 space then we get

Question 15.

**Higher Order Thinking** Write the steps you take to add 43 and 39 on a hundred chart.

Answer:

We are using the hundred chart to find the sum of 43 and 39

In the hundred charts, we start at 43 and down to 4 rows and back to 1 space then we get 82

43 + 39 = 82

Question 16.

**Assessment Practice** which has a sum of 35? Choose all that apply.

☐ 15 + 20

☐ 16 + 19

☐ 20 + 15

☐ 30 + 15

Answer:

15 + 20 has a sum of 35.

16 + 19 has a sum of 35

20 + 15 has a sum 0f 35

### Lesson 3.2 Add Tens and Ones on an Open Number Line

**Solve & Share**

How can you use the open number line to find 35 + 24?

Write an equation to show the sum. Explain your work.

I can … use an open number line to add tens and ones within 100.

Visual Learning Bridge

Convince Me! Explain how you can use an open number line to find 56 + 35.

**Guided Practice**

Use an open number line to find each sum.

Question 1.

59 + 24 = _________

Answer: 59 + 24 = 83

Question 2.

47 + 25 = _________

Answer:

First, draw a line.

Represent the numbers on the line.

The first number is 47 and counts by 20 then it gets 67 and hump 5 then we get 72.

Count the numbers and draw an arrow

47 + 25 = 72

**Independent Practice**

Use an open number line to find each sum.

Question 3.

34 + 15 = ________

Answer:

First, draw the line.

Represent the numbers on the line.

The first number is 34 and counts by 10 then it gets 44 and 5 then we get 49.

Count the numbers and draw an arrow.

34 + 15 = 49

Question 4.

34 + 46 = ________

Answer:

34 + 46 = 80

First, draw the Line.

Represent the number on the line.

The first number is 34 and counts by 20 then it gets 54 and counts again 20 then it gets 74 and jump to 6 then it gets 80.

Count the numbers and draw an arrow

Question 5.

16 + 28 = _________

Answer:

16 + 28 =44

First, draw the Line.

Represent the number on the line.

The first number is 16and counts by 10 then it gets 26 and jumps to 2 then it gets 28.

Count the numbers and draw an arrow.

Question 6.

59 + 26 = ________

Answer: 59 + 26 = 85

First draw the Line.

Represent the number on the line.

The first number is 59 and counts by 20 then it gets 79 and jumps to 6 then it gets 85.

Count the numbers and draw an arrow.

Question 7.

**Number Sense** Matt found 55 + 28 using the open number line below. Is his work correct? Explain.

Answer: 55 + 28 = 83

**Problem Solving**

Use the open number line to solve each problem below.

Question 8.

Reason There are 24 apples in a basket. There are 19 apples on a tray. How many apples are there in all?

_________ apples

Answer: Apples in a basket = 24

Apples in a tray = 19

Total number of apples = 24 + 19 = 43

Using the number line.

First, draw the Line.

Represent the number on the line.

The first number is 24 and counts by 10 then it gets 34 and jumps to 9 then it gets 43.

Count the numbers and draw an arrow.

Question 19.

Reason Jamie has 27 more berries than Lisa. Lisa has 37 berries. How many berries does Jamie have?

_________ berries

Answer:

Lisa has berries = 37

Jamie has berries = 27 berries more than Lisa

Jamie has berries = 37 + 27 =64

First draw the Line.

Represent the number on the line.

The first number is 37 and counts by 20 then it gets 54 and jumps to 9 then it gets 80.

Count the numbers and draw an arrow.

Question 10.

**Higher Order Thinking** Use two different number lines to show that 34 + 23 has the same value as 23 + 34.

Answer:

34 + 23 = 57

First, draw the Line.

Represent the number on the line.

The first number is 34 and counts by 20 then it gets 54 and jumps to 3 then it gets 57.

Count the numbers and draw an arrow.

23 + 34 = 57

First, draw the Line.

Represent the number on the line.

The first number is 23 and counts by 30 then it gets 53 jumps to 3 then it gets 57.

Count the numbers and draw an arrow.

Question 11.

**Assessment Practice** Use the numbers on the cards. Write the missing numbers under the number line to show how to find the sum.

43 + 25 = _________

Answer:

43 + 25 = 68

### Lesson 3.3 Break Apart Numbers to Add

**Solve & Share**

Josh has 34 cans to recycle. Jill has 27 cans. How many cans do they have in all? Solve any way you choose. Use drawings and equations to explain your work.

I can … break apart numbers into tens and ones to find their sum.

Visual Learning Bridge

Convince Me! Explain how you can break apart 28 to find 33 + 28.

**Guided Practice**

Break apart the second addend to find the sum. Show your work. Use an open number line to help.

Question 1.

**Independent Practice**

Break apart the second addend to find the sum. Show your work. Draw an open number line to help.

Question 2.

42 + 16 = ________

Answer:

42 + 16 =

42 + 10 + 6

52 + 6 = 58

First draw the Line.

Represent the number on the line.

The first number is 42 and counts by 10 then it gets 52 and jumps to 6 then it gets 58.

Count the numbers and draw an arrow.

Question 3.

36 + 44 = ________

Answer:

36 + 44

36 + 40 + 4

76 + 4 = 80

First draw the Line.

Represent the number on the line.

The first number is 36 and counts by 20 then it gets 56 and counts again by 20 ten we get 76 and jump to 4 then it gets 80.

Count the numbers and draw an arrow.

Question 4.

41 + 37 = ________

Answer:

41 + 37

41 + 30 + 7

71 + 7 = 78

First draw the Line.

Represent the number on the line.

The first number is 41 and counts by 30 then it gets 71 and jumps to 7 then it gets 78.

Count the numbers and draw an arrow.

Question 5.

35 + 47 = ________

Answer:

35 + 47

35 + 40 + 7

75 + 7 = 82

First draw the Line.

Represent the number on the line.

The first number is 35 and counts by 40 then it gets 75 and jumps to 7 then it gets 82.

Count the numbers and draw an arrow.

Question 6.

32 + 28 = ________

Answer:

32 + 28

32 + 20 + 8

52 + 8 = 60

First draw the Line.

Represent the number on the line.

The first number is 32 and counts by 20 then it gets 52 and jumps to 8 then it gets 60.

Count the numbers and draw an arrow.

Question 17.

48 + 27 = ________

Answer:

48 + 27

48 + 20 + 7

68 + 7 = 75

First draw the Line.

Represent the number on the line.

The first number is 48 and counts by 20 then it gets 68 and jumps to 7 then it gets 75.

Count the numbers and draw an arrow

Question 8.

**Number Sense** Write the digit that makes each equation true.

Answer:

36 + 52 = 88

Here the digit 2 makes the equation true.

28 + 47 = 75

Here the digit 7 makes the equation true.

14 + 43 = 57

Here the digit 3 makes the equation true.

53 + 29 = 82

Here the digit 9 makes the equation true.

**Problem Solving**

Solve each problem. Show your work.

Question 9.

Amir planted 35 trees. Juan planted 27 trees. How many trees did they plant in all?

________ trees

Answer:

Given that,

Total number of trees planted by Amir = 35

Total number of trees planted by Juan = 27

Total number of plants planted by Amir and Juan = 35 + 27 = 62

Question 10.

Carmen has 18 pennies. Patrick has 12 more pennies than Carmen. How many pennies does Patrick have?

________ pennies

Answer:

Given that,

Total number of pennies at Carmen = 18

Total number of pennies at Patrick more than Carmen = 12

Total number of pennies at Patrick = 18 + 12 = 30

Question 11.

**Higher Order Thinking** Use the numbers on the cards. Use each number once to write a true equation.

Answer:

The numbers on the card are 3, 2, 8

First, write the 2 in the first empty box then we get 52, and write the 3 in the second empty box then we get 34

By adding 52 and 34 we get 86. Write the 8 in the third box.

The true equation is

52 + 34 = 86

Question 12.

**Assessment Practice** which has a sum of 67? Choose all that apply.

Answer:

15 + 52 = 67

### Lesson 3.4 Add Using Compensation

**Solve & Share**

27 + 16 = ________

Draw counters on the ten frames to show each addend. Then show how you can move some counters to make it easier to find the sum. Explain your work.

I can … break apart addends and combine them in different ways to make numbers that are easy to add mentally.

Visual Learning Bridge

Convince Me! Solve.

19 + 26 = ☐

Explain how you can change the addends to make them easier to add.

**Guided Practice**

Use compensation to make numbers that are easier to add. Then solve. Show your work.

Question 1.

17 + 9 = ________

Question 2.

16 + 14 = __________

Answer:

**Independent Practice**

Use compensation to make numbers that are easier to add. Then solve. Show your work.

Question 3.

33 + 19 = __________

Answer:

33 + (10 + 9)

(33 + 10) + 9

43 + 9 = 52

Question 4.

28 + 8 = __________

Answer:

28 + (2 + 6)

(28 + 2) + 6

30 + 6 = 36

Question 5.

27 + 36 = __________

Answer:

27 + ( 30 + 6)

(27 + 30) + 6

57 + 6 = 63

Question 6.

**Number Sense** Explain how you can use compensation to make numbers that are easy to add. Solve. Show your work.

28 + 37 =

______ + ______ =

Answer:

28 + 37 =

28 + ( 30 + 7)

(28 + 30) + 7

58 + 7 = 65

Question 7.

**Higher Order Thinking** Show two different ways you could use compensation to make numbers that are easy to add. Solve. Show your work.

17 + 26 =

Answer:

17 + 26

17 + (20 + 6)

(17 + 20) + 6

37 + 6 = 43

**Problem Solving**

Use compensation to make numbers that are easier to add. Then solve. Show your work.

Question 8.

Explain Bella said there is only one way to rewrite this problem to make the numbers easier to add. Is she correct? Explain. Then solve.

42 + 29 =

Answer:

42 + 29

42 + (20 + 9)

(42 + 20) + 9

62 + 9 = 71

Question 9.

Vocabulary Show two different ways to use compensation to find the sum. Then solve.

58 + 35 =

What number is close to 58 or 35?

Answer:

58 + 35

58 + (30 + 5)

(58 + 30) + 5

88 + 5 = 92

Question 10.

**Higher Order Thinking** Show two different ways to use compensation to find the sum. Then solve.

37 + 16 + 5 =

Answer:

37 + (10 + 6) + 5

(37 + 10) + 6 + 5

47 + 6 + 5

47 + 11

47 +(10 + 1)

(47 + 10) + 1

57 + 1= 58

Question 11.

**Assessment Practice** which is equal to 42 + 18? Choose all that apply.

☐ 58

☐ 40 + 20

☐ 40 + 10 + 8

☐ 50 + 10

Answer:

The equation 40 + 20 and 50 + 10 are equal to 42 + 18

### Lesson 3.5 Practice Adding Using Strategies

**Solve & Share**

Tameka has 39 blocks. Kim has 43 blocks. How many blocks do they have in all? Choose any strategy. Solve. Show and explain your work.

I can … choose a strategy to help me add two-digit numbers.

_________ bolcks

Visual Learning Bridge

Convince Me! In 66 + 25 above, why was 4 added to 66 and then subtracted from 95?

**Guided Practice**

Find each sum. Use any strategy. Show your work.

Question 1.

Question 2.

67 + 26 = ___________

Answer:

67 + 26 =

67 + 20 + 6

87 + 6 = 93

**Independent Practice**

Find each sum. Use any strategy. Show your work.

Question 3.

33 + 52 = ___________

Answer:

33 + 52 =

33 + 50 + 2

73 + 2 = 75

Question 4.

27 + 6 = ___________

Answer:

27 + 6 = 33

Question 5.

___________ = 49 + 45

Answer:

49 + 45

49 + 40 + 5

89 + 5 = 94

Question 6.

57 + 12 = ___________

Answer:

57 + 12

57 + 10 + 2

67 + 2 = 69

Question 7.

___________ = 63 + 20

Answer:

66 + 20 = 86

Question 18.

14 + 58 = ___________

Answer:

14 + 58

14 + 50 + 8

64 + 8 = 72

Question 9.

45 + 55 = ___________

Answer:

45 + 55

45 + 50 + 5

95 + 5 = 100

Question 10.

87 + 9 = ___________

Answer:

87 + 9 = 96

Question 11.

19 + 61 = ___________

Answer:

19 + 61

19 + 60 + 1

79 + 1 = 80

**Number Sense** Write the digit that makes each equation true.

Question 12.

45 + 1☐ = 61

Answer:

45 + 16 = 61

The digit 6 makes the equation true.

Question 13.

84 = ☐8 + 56

Answer:

84 = 28 + 56

The digit 2 makes the equation true.

Question 14.

3☐ + 19 + 56

Answer:

30 + 19 + 56 = 105

The digit 0 makes the equation true

**Problem Solving**

Use the hundred chart to solve each problem. Be prepared to explain your work.

Question 15.

Reasoning Martin has 44 marbles. Carol has 39 marbles. Steve has 90 marbles. How many marbles do Martin and Carol have in all? Do they have more or fewer marbles than Steve?

_______ marbles

Circle:

more

fewer

Answer:

Given that,

Total number of marbles at Martin = 44

Total number of marbles at Carol = 39

Total number of marbles at Steve = 90

Total number of marbles at Martin and Carol = 44 + 39

Using a hundred charts find the sum of 44 + 39

In the hundred charts we start at 44 then down to 3 rows we get 74 and front to 4 space then we get 78

44 + 39 = 78

They both them have fewer marbles than Steve.

Question 16.

**Higher Order Thinking** José collected 32 leaves on Saturday. On Sunday, he collected 14 more leaves than he did on Saturday.

How many leaves did José collect in all?

________ leaves

Answer:

Given that

Total number of leaves Jose collected on Saturday = 32

Total number of leaves Jose collected on Sunday = 14

Total number of leaves they collected = 32 + 14 = 46

Question 17.

Lucita wants to use an open number line to find 53 + 18. Show how Lucita can use an open number line to find 53 + 18.

Answer:

53 + 18 = 71

First, draw the Line.

Represent the number on the line.

The first number is 53 and counts by 10 then it gets 63 and jumps to 8 then it gets 71.

Count the numbers and draw an arrow.

Question 18.

**Assessment Practice** Maria used a hundred chart to find a sum. She started at 68. Then she moved down 3 rows and back I space. Which number did she land on?

A. 88

B. 97

C. 98

D. 99

Answer:

Maria started at 68

She moved down to three rows is 98

And she back to 1 space then his number is 97

### Lesson 3.6 Solve One-Step and Two-Step Problems

**Solve & Share**

The red team has 15 more points than the blue team. The blue team has 36 points. How many points does the red team have?

Choose any strategy. Solve. Explain your work.

I can … use drawings and equations to solve one-step and two-step problems.

Visual Learning Bridge

Convince Me! What steps did you take to find the number of tickets Amy sold? Explain.

**Guided Practice**

Solve the two-step problem. Show your work.

Question 1.

Steve read 15 books. Sam read 9 fewer books than Steve. Dixon read 8 more books than Sam. How many books did Sam read?

Sam read _______ books.

sam read 6 books.

How many books did Dixon read?

Dixon read _______ books.

Dixon read 14 books.

**Independent Practice**

Solve the problems below. Show your work.

Question 2.

Brian has 17 fewer marbles than Kyle. Brian has 21 marbles. How many marbles does Kyle have?

________ marbles

Answer:

Given that,

Total number of marbles at Brain = 21

The total number of marbles at Brain has fewer than Kyle = 17

Total number of marbles marbles at Kyle = 21 + 17 = 38

Question 3.

Clint catches 7 frogs. 3 frogs hop away. Then Clint catches 6 more frogs. How many frogs does Clint have now?

_________ frogs

Answer:

Given that,

Total number of frogs the Clint catches = 7

Total number of Frogs hop away = 3

Clint catches another more frogs = 6

Total number of frogs at Clint = 7 – 3 + 6 = 10

Question 4.

Erwin sees 23 birds in a tree. Then 18 more birds come. How many birds does Erwin see now?

_________ birds

Answer:

Given that,

Erwin sees the total number of birds in a tree = 23

More birds come on the tree = 18

Total number of birds that seen bye the Erwin = 23 + 18 = 41

Question 5.

There are 31 bluefish in a pond. There are also 8 goldfish and 3 redfish in the pond. How many fish are in the pond?

________ fish

Answer:

Given that

Total number of Blue fishes in a pound = 31

Total number of Goldfishes in a pound = 8

Total number of Red fishes in a pound = 3

Total number of fishes in a pound = 31 + 8 + 3 = 42

Question 6.

**Higher Order Thinking** Mr. Leu buys 6 bananas. Then he buys 8 more bananas. He gives some bananas to Mr. Shen. Now Mr. Leu has 5 bananas. How many bananas did Mr. Leu give to Mr. Shen?

_________ bananas

Answer:

Given that,

Mr. Leu buys bananas = 6

He buys more bananas = 8

Total bananas at Mr. Leu = 6 + 8 = 14

Mr. Leu gave some bananas to the Mr. Shen

Mr. Leu left only 5 bananas

Mr. Leu gave to Mr. Shen = 14 – 5 = 9

**Problem Solving**

Solve the problems below. Show your work.

Question 7.

There are 21 more green crayons than blue crayons. There are 14 blue crayons. How many green crayons are there?

__________ green crayons

Answer:

Given that,

Total number of Blue crayons = 14

Green crayons are 21 more than blue crayons.

Total number of Green crayons = 14 + 21 = 35

Question 8.

Make Sense Dan swims 4 laps on Monday. He swims 5 laps on Tuesday. Then he swims 9 laps on Wednesday. How many laps does Dan swim in all?

_________ laps

Answer:

Given that,

Dan swims on Monday = 4 laps

Dan swims on Tuesday = 5 laps

Dan swims on Wednesday = 9 laps

Total number of laps that Don swim = 4 + 5 + 9 = 18

Question 9.

**Higher Order Thinking** Robert has 20 blueberries. He has 10 more blueberries than Janessa. He has 14 fewer blueberries than Amari. How many blueberries does Janessa have? How many blueberries does Amari have?

Janessa has ________ blueberries.

Amari has __________ blueberries.

Answer:

Given that,

A robot has 20 blueberries

He has 10 more blueberries than Janessa

Janessa has blueberries = 20 – 10 = 10

The robot has 14 blueberries fewer than Amari

Amari has total number of blueberries = 20 + 14 = 34

Question 10.

**Assessment Practice** Billy saw 19 animals at Grayson Zoo in the morning. He saw 17 more animals after lunch. How many animals did Billy see in all?

__________ animals

Answer:

Given that,

Billy saw animals at Grayson Zoo in the morning = 19

Billy saw animals at Grayson Zoo in the afternoon = 17

Total number of animals that Billy saw = 19 + 17

### Lesson 3.7 Problem Solving

**Construct Arguments
Solve & Share**

Carrie has 16 more red apples than green apples. She has 24 green apples. How many red apples are there?

Use any strategy to solve. Use pictures, numbers, or words to explain your thinking and work.

I can … use pictures, numbers, and words to explain why my thinking and work are correct.

**Thinking Habits**

Construct Arguments

How can I use math to explain why my work is correct?

Am I using numbers and symbols correctly?

Is my explanation clear?

Visual Learning Bridge

Convince Me! Are both math arguments above clear and complete? Explain.

**Guided Practice**

Solve. Use pictures, words, or numbers to make a math argument. Show your work.

Question 1.

There are 16 chickens in the yard. There are 19 chickens in the barn. There are 30 nesting boxes. Will all of the chickens have a nest? Explain.

Answer:

Given that,

Total number of Chickens in a yard = 16

Total number of Chickens in a barn = 19

Total number of Chickens in a nesting = 30

Total number of chickens = 16 + 19 = 35

5 chickens have no nest

**Independent Practice**

Solve each problem. Use pictures, words, or numbers to make a math argument. Show your work.

Question 2.

Greg had 45 sports cards. Jamal gives him 26 more cards. How many sports cards does Greg have now?

_________ sports cards

Answer:

Given that,

Total number of sports cards at Grah = 45

Jamal gives more cards to Grah = 26

Total number of sports cards at Grah = 45 + 26 = 71

Question 3.

Denise drew 8 stars with crayons. Then she drew 6 more stars. Trina drew 5 stars. How many fewer stars did Trina draw than Denise?

________ fewer stars

Answer:

Given that,

Denise draw stars with crayons = 8

She draws more stars = 6

Total number of stars drawn by Denise = 8 + 6 = 14

Trina draw a star = 5

14 – 5 = 9

Trina draw 9 fewer stars than Denise

**Problem Solving**

Performance Task

Bean Bag Toss Evan and Pam each throw two bean bags. Points are added for a score. Pam’s total score is 100. Which two numbers did Pam’s bean bags land on?

Question 4.

Make Sense What information is given? What do you need to find?

Answer:

In the above task, Pam and Evan play a bean bag toss game.

The score Pam’s is 100

The numbers that Pam’s bean bag lands on are 56 and 44.

By adding 56 and 44 we get 100.so, the beam bag lands on 56 and 44.

Question 5.

Explain Which numbers did Pam’s bags land on? Explain how you know.

Answer:

Given that,

Pam’s bags land on 56 and 44

The total score Pam’s is 100

By adding 56 and 44 we get 100

So, Pam’s bags are landed on 56 and 44.

Question 6.

Explain How could you use a hundred charts to solve the problem? Explain.

Answer:

using a hundred charts for example you went to find the sum of 10 + 15.

first, mark the 10 in the hundred charts and down to 1 row and back to 5 places then we get 15 has the answer.

This is the way to solve the problem using a hundred charts.

### Topic 3 Fluency Practice Activity

**Find & Match**

Find a partner. Point to a clue. Read the clue.

Look below the clues to find a match. Write the clue letter in the box next to the match.

Find a match for every clue.

I can … subtract within 20.

Clues

A. Every difference equals 3.

B. Every difference is less than 2.

C. Every difference equals 11 – 5.

D. Exactly two differences are equal.

E. Every difference is greater than 8.

F. Exactly three differences are odd.

G. Every difference equals 16 – 8.

H. Exactly three differences are even.

### Topic 3 Vocabulary Review

Understand Vocabulary

Word List

- bar diagram
- break apart
- compensation
- mental math
- ones
- open number line
- tens

Question 1.

Circle the numbers that have a 3 in the one’s place.

33

45

13

38

Answer:

In the above-given numbers, 33 and 13 has 3 in the one’s place then circle the 33 and 13.

Question 2.

Cross out the numbers that do NOT have an 8 in the tens place.

80

18

78

89

Answer:

In the above-given numbers, 18 and 78 do not have 8 in the ten’s place. Then cross out the 18 and 78.

Question 3.

Write an equation to show how to break apart 54 by place value.

Answer: 50 + 4

Question 4.

Use the open number line to find 38 + 23. Add the tens and then add the ones.

Answer:

38 + 23

38 + (20 + 3)

58 + 3 = 61

First draw the Line.

Represent the number on the line.

The first number is 38 and counts by 20 then it gets 54 and jumps to 3 then it gets 61.

Count the numbers and draw an arrow.

**Use Vocabulary in Writing**

Question 5.

Describe a way to find 47 + 18. Use terms from the Word List.

Answer:

47 + (10 + 8)

(47 + 10) + 8

57 + 8 = 65

### Topic 3 Reteaching

**Set A**

You can use a hundred charts to help you add. Find 62 + 12.

Start at 62. Move down 1 row to add the 1 ten in 12.

Then move over 2 columns to add the 2 ones in 12.

Use a hundred charts to find each sum.

Question 1.

85 + 15 = _______

Answer:

Using the hundred chart the sum of 85 + 15 is

In the hundred charts, we start at the 85 then down to 1 row then we get 95, and move front to 5 space then we get 100.

85 + 15 = 100

Question 2.

60 + 23 = _________

Answer:

Using the hundred chart the sum of 60 + 23 is

In the hundred charts, we start at 60 and then move down to 2 rows then we get 80 and move front to 3 space then we get 83

60 + 23 = 83

**Set B**

You can use an open number line to find 49 + 32.

Place 49 on the number line. There are 3 tens in 32. So, count on by 10 three times. There are 2 ones in 32. So, count on 2 from 79.

So, 49 + 32 = 81

Use an open number line to find each sum.

Question 3.

35 + 13 = ________

Answer:

35 + 13 = 48

First, draw the Line.

Represent the number on the line.

The first number is 35 and counts by 10 then it gets 45 and jumps to 3 then it gets 48.

Count the numbers and draw an arrow.

Question 4.

47 + 26 = _________

Answer:

47 + 26 = 73

First, draw the Line.

Represent the number on the line.

The first number is 47 and counts by 20 then it gets 67 and jumps to 6 then it gets 73.

Count the numbers and draw an arrow.

**Set C**

Find 55 + 17.

Break apart 17 into 10+ 7.

Break apart the second addend to find the sum. Show your work.

Question 5.

53 + 28 = _________

Answer:

53 + 28

53 + 20 + 8

73 + 8 = 81Question 6.

78 + 19 = _________

Answer:

78 + 19

78 + 10 + 9

88 + 9 = 97

**Set D**

Find 48 + 27.

48 is close to 50. So, take 2 from 27 and give it to 48 to make 50.

48 + 27 = ?

Use compensation to make numbers that are easier to add. Then solve. Show your work.

Question 7.

17 + 46 = ________

Answer:

17 + 46

17 + 40 + 6

57 + 6 = 63

Question 8.

29 + 57 = ________

Answer:

29 + 57

29 + 50 + 7

79 + 7 = 86

**Set E**

You can use different strategies and tools to find a sum.

You can:

- Use a hundred chart
- Use an open number line
- Break apart one addend
- Use compensation

Solve. Show your work.

Question 9.

Ted’s puzzle has 37 more pieces than his brother’s puzzle. His brother’s puzzle has 48 pieces. How many pieces does Ted’s puzzle have?

________ pieces

Answer:

Given that,

Ted’s puzzle has more pieces than her brother = 37

His brother puzzle has pieces = 48

Total number of pieces does Ted’s have = 48 + 37 = 85

**Set F**

Marla walks 12 blocks on Monday. On Tuesday, she walks 4 fewer blocks. How many blocks does Marla walk in all?

Blocks Marla walks on Tuesday:

Solve the two-step problem.

Question 10.

Wyatt has 16 crayons. He buys 24 new crayons. Then he finds 7 more crayons. How many crayons does Wyatt have now?

________ crayons

Answer:

Total number of crayon = 47

**Set G**

**Thinking Habits**

Construct Arguments

How can I use math to explain my work?

Am I using numbers and symbols correctly?

Is my explanation clear?

Solve the problem. Use words and numbers to make a math argument.

Question 11.

A second-grade class sets a goal to collect 70 cans. One week they collect 38 cans. The next week they collect 35 cans. Do they meet their goal?

Answer:

Given that,

A second-grade class set a goal to collect cans = 70

One week the second-grade class set collect cans = 38

Next week the second-grade class set collect cans = 35

Total number of cans they collected = 38 + 35 =73

Yes they meet their goal by collecting 73 cans out of 70

### Topic 3 Assessment Practice

Question 1.

Which have a sum of 43? Choose all that apply.

☐ 33 + 10

☐ 28 + 13

☐ 10 + 33

☐ 19 + 24

☐ 10 + 21

Answer:

33 + 10 has a sum of 43

10 + 33 has a sum of 43

19 + 24 has a sum of 43

Question 2.

Terry has 63 crayons. She gets 25 more crayons. How many crayons does Terry have in all? Show your work.

________ crayons

Answer:

Given that,

Total number of crayons near Terry = 63

Tenny get more crayons = 25

Total number of crayons at Terry = 63 + 25 = 88

Question 3.

Which equation does this number line show?

A. 57 + 28 = 85

B. 57 + 38 = 95

C. 57 + 33 = 90

D. 57 + 39 = 96

Answer:

57 + 38 = 95

Question 4.

Use the numbers on the cards. Write the missing numbers under the number line to show how to find the sum of 40 + 35.

Answer:

Question 5.

Colin has 54 pennies and 28 nickels. How many coins does Colin have?

Break apart the second addend to solve. Show your work.

________ coins

Answer:

Given that,

Total number of pennies near Colin = 54

Total number of nickels near Colin = 28

Total number of coins near colin = 54 + 28

54 + (20 + 8)

(54 + 20) + 8

74 + 8 = 82

Question 6.

Show how to add 68 + 16 using the open number line.

68 + 16 = ___________

Answer:

68 + 16 = 84

First draw the Line.

Represent the number on the line.

The first number is 68 and counts by 10 then it gets 78 and jumps to 6 then it gets 84.

Count the numbers and draw an arrow.

Question 7.

Part A

Show how you can use an open number line to find 44 + 27.

44 + 27 = _________

Answer:

44 + 27 = 71

First draw the Line.

Represent the number on the line.

The first number is 44 and counts by 20 then it gets 64 and jumps to 7 then it gets 71.

Count the numbers and draw an arrow.

Part B

In words, tell how you used the open number line to find the sum.

Answer:

Suppose we have a sum that is 14 + 13

Then draw a line and represent the numbers on a line and place a 14 on the line shift 10 from the 14 we get 24 then jump to 3 then we get 27.

The sum of 14 + 13 = 27.

Question 8.

Which have a sum of 70? Choose all that apply.

☐ 35 + 35

☐ 40 + 30

☐ 45 + 45

☐ 50 + 200

☐ 30 + 30

Answer:

35 + 35

40 + 30

Question 9.

Lisa has 18 markers. Adam has 22 markers. Will all of the markers fit in a box that can hold 38 markers?

Make a math argument. Explain.

Answer:

Given that,

Total number of markers near Lisa = 18

Total number of markers near Adam = 22

Total number of Markers fit in a box = 38

Total number of markers = 18 + 22 = 40

Total markers are not fit into a box.

Question 10.

Ted has 52 cards in a box. Tyrone has 48 more cards than Ted. How many cards does Tyrone have? Show your work to explain your thinking.

________ cards

Answer:

Given that

Ted has cards in a box = 52

Tyrone has more card than Ted = 48

Total number of cards at Tyrone = 52 + 48 = 100

Question 11.

Which are equal to 47 + 25? Choose all that apply.

☐ 40 + 20 + 7 +5

☐ 40 + 20 + 12

☐ 50 + 12

☐ 50 + 22

Answer:

To find the sum of 47 + 25 we apply the 40 + 20 + 7 + 5

Question 12.

Emma has 46 rocks. She gets 25 more rocks from Gus. How many rocks does Emma have now?

________ rocks

Answer:

Given that,

Emma has rocks = 46

She get more rocks = 25

Total number of rocks at Emma = 46 + 25 = 71

Question 13.

Is each sum 64? Choose Yes or No.

Answer:

Question 14.

Break apart the second addend to find 56 + 38. Show your work.

56 + 38 = ________

Answer:

56 + 38

56 + 30 + 8

86 + 8 = 94

Question 15.

Write an equation to solve each part of the two-step problem.

Ken has 45 stamps. He uses 20 stamps. Then he buys 7 more stamps. How many stamps does he have now?

Ken has ________ stamps.

Answer:

Given that,

Ken has total number of stamps = 45

He used total number of stamps = 20

He buy another stamps = 7

Total number of stamps Ken have = 45 – 20 + 7

25 + 7 = 32

Question 16.

Show two different ways to find 28 + 49 using compensation.

Way 1

Way 2

Answer:

Way 1: 28 + 49 = 77

Way 2: 28 + 49

28 + 40 + 9

68 + 9 = 77

### Topic 3 Performance Task

**Popcorn Sales**

A second-grade class is selling popcorn to help pay for a field trip.

This table shows how many boxes some students have sold.

Question 1.

How many boxes of popcorn did Ted and Mary sell in all? Use the open number line to solve. Show your work.

_________ boxes

Answer:

Given that,

Number of popcorn did Ted sell = 21

Number of popcorn did Mary sell = 34

Total number of popcorn box sell = 21 + 34 = 55

First draw the Line.

Represent the number on the line.

The first number is 21and counts by 30 then it gets 51and jumps to 4 then it gets 80.

Count the numbers and draw an arrow.

Question 2.

James says that Mary and Nancy sold more boxes in all than Darnell and Ted sold in all. Do you agree with him?

Circle:

Yes

No

Explain your answer.

Answer:

Given that,

Total number of boxes sold by Mary = 34

Total number of boxes sold by Nancy = 19

Total number of boxes sold by Mary and Nancy = 34 + 19 = 43

Total number of boxes sold by Darnell = 28

Total number of boxes sold by Ted = 21

A total number of boxes sold by Darnell and Ted = 21 + 28 = 49

James said wrong that Mary and Nancy sold fewer boxes than Darnell and Ted.

Question 3.

Which two students sold a total of 55 boxes? Use any strategy to solve. Show your work.

Circle the names of the two students.

Question 4.

Nancy sold 18 fewer boxes than Lucas. How many boxes did Lucas sell?

Part A

Solve the problem. Show your work and explain your thinking.

________ boxes

Answer:

Given that,

Nancy sold fewer boxes than Lucas = 18

Total number of boxes that Nancy sold = 19

Total number of boxes that Lucas sold more than Nancy = 19 – 18 = 1

Part B

Look at the list of strategies on the left. To show that your answer in Part A is correct, use a different strategy to solve the problem.

Answer: