Go through the enVision Math Common Core Grade 1 Answer Key Topic 10 Use Models and Strategies to Add Tens and Ones regularly and improve your accuracy in solving questions.

## enVision Math Common Core 1st Grade Answers Key Topic 10 Use Models and Strategies to Add Tens and Ones

enVision STEM Project: Watch the Stars

Find Out Talk to friends and relatives about stars. Discuss why the stars you see in the sky change from night to night.
Journal: Make a Book Show what you found out. In your book, also:

• Draw the stars you can see from where you live.

Review What You Know

Vocabulary

Question 1.
Circle the digit that shows how many ones.
91

The digit that shows many ones is 1.

Explanation:
In the above-given question,
given that,
the number is 91.
9 is in the tens place.
1 is in one place.
so we have to circle for one.

Question 2.
Circle the digit that shows how many tens.
13

The digit that shows many tens is 1.

Explanation:
In the above-given question,
given that,
the number is 13.
1 is in the tens place.
3 is in one place.
so we have to circle for one.

Question 3.
Circle the symbol that tells you add.
+ – =

The symbol is +.

Explanation:
In the above-given question,
given that,
for example:
3 + 2.
5.
here we did the addition operation.

Question 4.
Write an addition equation to match the picture.

The equation is 9 + 5 = 14.

Explanation:
In the above-given question,
given that,
there are 9 blue flowers.
there are 5 red flowers.
9 + 5 = 14.

Question 5.
Noah mows 7 lawns. Mari mows 13 lawns. How many lawns did the two friends mow in all? Write an addition equation to solve.
__ + __ = ____

The addition equation is 7 + 13 = 20.

Explanation:
In the above-given question,
given that,
Noah mows 7 lawns.
Mari mows 13 lawns.
7 + 13 = 20.

Hundred Chart

Question 6.
Fill in the missing numbers on the part of the hundred chart.

The missing numbers are 42, 55, 58, 63, and 70.

Explanation:
In the above-given question,
given that,
the numbers are from 41 to 70.
the missing numbers on the part of the hundred charts:
42, 55, 58, 63, and 70.

pick a Project

PROJECT 10A

Has anyone ever called you the wrong name?
Project: Make a Manatee Facts Book

PROJECT 10B
Have you ever aimed at a target?
Project: Play a Target Toss Game

PROJECT 10C
What is as colorful as a butterfly?
Project: Make a Leaf and Egg Model

PROJECT 10D
What would life be like without bones?
Project: Write and Draw an Octopus Story

### Lesson 10.1 Add Tens Using Models

Solve & Share

How are these addition problems alike? Talk to a partner about how you can use the first sum to help you find the second.

3 + 5 = 8.
30 + 50 = 80.

Explanation:
In the above-given question,
given that,
3 + 5 = 8.
3 is in the tens place and 0 is in one place.
30 + 50 = 80.

Visual Learning Bridge

Convince Me!

6 tens + 3 tens = 90.

Explanation:
In the above-given question,
given that,
6 + 3 = 9.
6 tens + 3 tens.
6 tens = 60.
3 tens = 30.
60 + 30 = 90.

Guided Practice

Write the numbers to complete each equation.

Question 1.

30 + 40 = 70.

Explanation:
In the above-given question,
given that,
3 tens + 4 tens.
3 tens = 30.
4 tens = 40.
3 tens + 4 tens = 70.

Question 2.

10 + 50 = 60.

Explanation:
In the above-given question,
given that,
1 tens + 5 tens.
1 tens = 10.
5 tens = 50.
1 tens + 5 tens = 60.

Independent Practice

Write the numbers to complete each equation.

Question 3.

20 + 20 = 40.

Explanation:
In the above-given question,
given that,
2 tens + 2 tens.
2 tens = 20.
2 tens = 20.
2 tens + 2 tens = 40.

Question 4.

50 + 30 = 80.

Explanation:
In the above-given question,
given that,
5 tens + 3 tens.
5 tens = 50.
3 tens = 30.
5 tens + 3 tens = 80.

Question 5.

30 + 10 = 40.

Explanation:
In the above-given question,
given that,
3 tens + 1 tens.
3 tens = 30.
1 tens = 10.
3 tens + 1 tens = 40.

Question 6.

10 + 10 = 20.

Explanation:
In the above-given question,
given that,
1 tens + 1 tens.
1 tens = 10.
1 tens = 10.
1 tens + 1 tens = 20.

Question 7.

40 + 40 = 80.

Explanation:
In the above-given question,
given that,
4 tens + 4 tens.
4 tens = 40.
4 tens = 40.
4 tens + 4 tens = 80.

Question 8.

20 + 50 = 70.

Explanation:
In the above-given question,
given that,
2 tens + 5 tens.
2 tens = 20.
5 tens = 50.
2 tens + 5 tens = 70.

Question 9.

30 + 30 = 60.

Explanation:
In the above-given question,
given that,
3 tens + 3 tens.
3 tens = 30.
3 tens = 30.
3 tens + 3 tens = 60.

Question 10.

10 + 40 = 50.

Explanation:
In the above-given question,
given that,
1 tens + 4 tens.
1 tens = 10.
4 tens = 40.
1 tens + 4 tens = 50.

Question 11.

50 + 40 = 90.

Explanation:
In the above-given question,
given that,
5 tens + 4 tens.
5 tens = 50.
4 tens = 40.
5 tens + 4 tens = 90.

Problem Solving
Add tens to solve. Use place-value blocks if needed.

Question 12.
Make Sense Alex and Annie each have 5 boxes of crayons. Each box has 10 crayons.
How many crayons do Alex and Annie have in all?
___ + ___ = ___
___ crayons

The number of crayons do Alex and Annie have in all = 100.

Explanation:
In the above-given question,
given that,
Alex and Annie each have 5 boxes of crayons.
Each box has 10 crayons.
5 x 10 = 50.
50 + 50 = 100.
so the number of crayons do Alex and Annie have in all = 100.

Question 13.
Make Sense Becky and Dan buy some bottles of juice. Becky buys 6 bottles. Dan buys 2 bottles. Each bottle of juice is enough for 10 people. How many people do Dan and Becky have enough juice for?
___ + __ = ___
___ people

The number of people do Dan and Becky have enough for = 80.

Explanation:
In the above-given question,
given that,
Becky and Dan buy some bottles of juice.
Each bottle of juice is enough for 10 people.
6 x 10 = 60.
2 x 10 = 20.
60 + 20 = 80.

Question 14.
Higher Order Thinking Bree says that she knows 4 + 3 = 7, so she also knows that 30 + 40 = 70. Is she correct? Explain how you know.

Yes, she was correct.

Explanation:
In the above-given question,
given that,
4 + 3 = 7.
30 + 40 = 70.
3 tens + 4 tens = 7 tens.
so she was correct.

Question 15.
Assessment Practice Which equation matches the picture?
A. 2 + 3 = 5
B. 3 + 2 = 5
C. 20+ 3 = 23
D. 20 + 30 = 50

Option D is correct.

Explanation:
In the above-given question,
given that,
2 tens + 3 tens.
2 tens = 20.
3 tens = 30.
20 + 30 = 50.
so option D is correct.

### Lesson 10.2 Mental Math: Ten More Than a Number

Solve & Share

Solve each problem. What pattern do you see in the totals?

15 + 10 = 25.
25 + 10 = 35.
55 + 10 = 65.

Explanation:
In the above-given question,
given that,
15 + 10 = 25.
25 + 10 = 35.
55 + 10 = 65.

Visual Learning Bridge

Convince Me!
Explain how you can use mental math to add 10 to 47.

10 + 47 = 57.

Explanation:
In the above-given question,
given that,
4 + 1 = 5.
47 + 10 = 57.
5 tens + 7 ones = 57.

Guided Practice

Use mental math to solve the problems.

Question 1.

10 + 25 = 35.

Explanation:
In the above-given question,
given that,
2 + 1 = 3.
25 + 10 = 35.
3 tens + 5 ones = 35.

Question 2.

10 + 12 = 22.

Explanation:
In the above-given question,
given that,
1 + 1 = 2.
12 + 10 = 22.
2 tens + 2 ones = 22.

Independent Practice

Use mental math to solve each equation.

Question 3.

58 + 10 = ___

10 + 58 = 68.

Explanation:
In the above-given question,
given that,
5 + 1 = 6.
58 + 10 = 68.
6 tens + 8 ones = 68.

Question 4.

44 + 10 = ___

10 + 44 = 54.

Explanation:
In the above-given question,
given that,
4 + 1 = 5.
44 + 10 = 54.
5 tens + 4 ones = 54.

Question 5.

35 + 10 = ___

10 + 35 = 45.

Explanation:
In the above-given question,
given that,
3 + 1 = 4.
35 + 10 = 45.
4 tens + 5 ones = 45.

Question 6.
10 + 72 = ___

10 + 72 = 82.

Explanation:
In the above-given question,
given that,
7 + 1 = 8.
72 + 10 = 82.
8 tens + 2 ones = 82.

Question 7.
87 + 10 = ___

10 + 87 = 97.

Explanation:
In the above-given question,
given that,
8 + 1 = 9.
87 + 10 = 97.
9 tens + 7 ones = 97.

Question 8.
31 + 10 = ___

10 + 31 = 41.

Explanation:
In the above-given question,
given that,
3 + 1 = 4.
31 + 10 = 41.
4 tens + 1 ones = 41.

Question 9.
18 + 10 = ___

10 + 18 = 28.

Explanation:
In the above-given question,
given that,
1 + 1 = 2.
18 + 10 = 28.
2 tens + 8 ones = 28.

Question 10.
10 + 26 = ___

10 + 26 = 36.

Explanation:
In the above-given question,
given that,
2 + 1 = 3.
26 + 10 = 36.
3 tens + 6 ones = 36.

Question 11.
9 + 10 = ___

10 + 9 = 19.

Explanation:
In the above-given question,
given that,
9 + 1 = 10.
9 + 10 = 19.
1 tens + 9 ones = 19.

Question 12.
Number Sense Winnie used place-value blocks to show 29 + 10. She said the answer is 30. Is Winnie correct? Explain how you know.

No, Winnie was not correct.

Explanation:
In the above-given question,
given that,
Winnie used place-value blocks to show 29 + 10.
29 + 10 = 39.
so Winnie was not correct.

Problem Solving

Use mental math to solve the problems below.

Question 13.
Reasoning Sam makes 15 dollars mowing lawns one day. He makes 10 dollars the next day. How many dollars did Sam make in all?
____ dollars

The number of dollars did Sam make in all = 25.

Explanation:
In the above-given question,
given that,
Sam makes 15 dollars mowing lawns one day.
He makes 10 dollars the next day.
15 + 10 = 25.
so the number of dollars did Sam make in all = 25.

Question 14.
Reasoning Tess solves 22 math problems. Then she solves 10 more math problems. How many math problems did Tess solve in all?

___ math problems

The math problems did Tess solve in all = 32.

Explanation:
In the above-given question,
given that,
Tess solves 22 math problems.
Then she solves 10 more math problems.
22 + 10 = 32.
2 + 1 = 3.
so the math problems did Tess solve in all = 32.

Question 15.
Higher Order Thinking Roger collects 75 cans. Ella collects some cans. Roger and Ella have 85 cans together. How many cans did Ella collect?
___ cans

The number of cans Ella collect = 10.

Explanation:
In the above-given question,
given that,
Roger collects 75 cans.
Ella collects some cans.
Roger and Ella have 85 cans together.
85 – 75 = 10.
so the number of cans Ella collect = 10.

Question 16.
Assessment Practice Match each pair of addends with their sum.

27 = 17 + 10.
86 = 76 + 10.
43 = 33 + 10.
51 = 41 + 10.
69 = 59 + 10.

Explanation:
In the above-given question,
given that,
27 = 2 tens + 7 ones.
86 = 8 tens + 6 ones.
43 = 4 tens + 3 ones.
51 = 5 tens + 1 ones.
69 = 6 tens + 9 ones.
27 = 17 + 10.
86 = 76 + 10.
43 = 33 + 10.
51 = 41 + 10.
69 = 59 + 10.

### Lesson 10.3 Add Tens and Ones Using a Hundred Chart

Solve & Share
Use a hundred chart to find these sums. 8 + 40 = ? 30 + 40 = ? 80 + 12 = ?
Show your work and tell how you found each sum.

Visual Learning Bridge

Convince Me!
How could you use the hundred chart to find the sum of 6 and 50?

Guided Practice

Use the part of the hundred chart to add.

Question 1.
2 + 12 = 14

2 + 12 = 14.

Explanation:
In the above-given question,
given that,
12 has 1 ten and 2 ones.
so 12 is 1 row down on the chart.
2 is 2 ones.
2 + 12 = 14.

Question 2.
5 + 40 = ___

5 + 40 = 45.

Explanation:
In the above-given question,
given that,
40 has 4 tens and 0 ones.
so 40 is 1 row down on the chart.
5 is 5 ones.
5 + 40 = 45.

Question 3.
13 + 20 = ___

13 + 20 = 33.

Explanation:
In the above-given question,
given that,
33 has 3 tens and 3 ones.
so 33 is 1 row down on the chart.
13 is  1 ten 3 ones.
13 + 20 = 33.

Question 4.
10 + 31 = ___

10 + 31 = 41.

Explanation:
In the above-given question,
given that,
41 has 4 ten and 1 ones.
so 31 is 1 row down on the chart.
10 is 10 ones.
10 + 31 = 41.

Question 5.

32 + 6 = ___

6 + 32 = 38.

Explanation:
In the above-given question,
given that,
32 has 3 ten and 2 ones.
so 32 is 1 row down on the chart.
6 is 6 ones.
6 + 32 = 38.

Independent Practice

Use the hundred chart to add.

Question 6.
7 + 60 = ____

7 + 60 = 67.

Explanation:
In the above-given question,
given that,
67 has 6 ten and 7 ones.
so 67 is 1 row down on the chart.
7 is 7 ones.
7 + 60 = 67.

Question 7.
33 + 20 = ___

33 + 20 = 53.

Explanation:
In the above-given question,
given that,
53 has 5 ten and 3 ones.
so 53 is 1 row down on the chart.
20 is 20 ones.
33 + 20 = 53.

Question 8.
20 + 18 = ___

18 + 20 = 38.

Explanation:
In the above-given question,
given that,
38 has 3 ten and 8 ones.
so 18 is 1 row down on the chart.
2 is 2 tens.
18 + 20 = 38.

Question 9.
5 + 13 = ___

5 + 13 = 18.

Explanation:
In the above-given question,
given that,
13 has 1 ten and 3 ones.
so 5 is 1 row down on the chart.
5 is 5 ones.
5 + 13 = 18.

Question 10.
3 + 26 = ___

3 + 26 = 29.

Explanation:
In the above-given question,
given that,
29 has 2 ten and 9 ones.
so 3 is 2 rows down on the chart.
3 is 3 ones.
3 + 26 = 29.

Question 11.
1 + 41 = ___

1 + 41 = 51.

Explanation:
In the above-given question,
given that,
51 has 5 ten and 1 ones.
so 1 is 4 rows down on the chart.
1 is 1 one.
1 + 41 = 51.

Question 12.
4 + 32 = ___

4 + 32 = 36.

Explanation:
In the above-given question,
given that,
36 has 3 ten and 6 ones.
so 3 is 3 rows down on the chart.
4 is 4 ones.
4 + 32 = 36.

Question 13.
56 + 2 = ___

2 + 56 = 58.

Explanation:
In the above-given question,
given that,
58 has 5 tens and 8 ones.
so 2 is 5 rows down on the chart.
2 is 2 ones.
2 + 56 = 58.

Question 14.
10 + 85 = __

10 + 85 = 95.

Explanation:
In the above-given question,
given that,
85 has 8 ten and 5 ones.
so 10 is 8 rows down on the chart.
10 is 10 ones.
10 + 85 = 95.

Question 15.
7 + 12 = ___

7 + 12 = 19.

Explanation:
In the above-given question,
given that,
19 has 1 ten and 9 ones.
so 7 is 1 row down on the chart.
7 is 7 ones.
7 + 12 = 19.

Question 16.
50 + 13 = ___

13 + 50 = 63.

Explanation:
In the above-given question,
given that,
63 has 6 ten and 3 ones.
so 13 is 4 rows down on the chart.
13 is 13 ones.
13 + 50 = 63.

Question 17.
71 + 5 = ___

71 + 5 = 76.

Explanation:
In the above-given question,
given that,
76 has 7 ten and 6 ones.
so 71 is 1 row down on the chart.
5 is 5 ones.
71 + 5 = 76.

Question 18.
Higher Order Thinking Sue had some stickers in a book. She bought 30 more stickers. Now she has 36 stickers in her book. How many stickers did Sue have in the book at the start?
_____ stickers

The number of stickers did Sue have in the book at start = 6.

Explanation:
In the above-given question,
given that,
Sue had some stickers in a book.
She bought 30 more stickers.
Now she has 36 stickers in her book.
36 – 30 = 6.
so the number of stickers did Sue have in the book at start = 6.

Problem Solving

Use the hundred chart to solve each problem below.

Question 19.
Use Tools Some hens lay 40 eggs. Then they lay 45 more eggs. How many eggs did the hens lay in all?
___ eggs

The number of eggs did the hens lay in all = 85.

Explanation:
In the above-given question,
given that,
Some hens lay 40 eggs.
Then they lay 45 more eggs.
40 + 45 = 85.
so the number of eggs did the hens lay in all = 85.

Question 20.
Use Tools 22 students are at the book fair. More students came to the book fair later. There are 72 students in all at the book fair. How many students came later?
____ students

The number of students who came later = 52.

Explanation:
In the above-given question,
given that,
22 students are at the book fair.
More students came to the book fair later.
There are 72 students in all at the book fair.
72 – 22 = 52.
so the number of students who came later = 52.

Question 21.
Higher Order Thinking Write a number story for 3 + 42.

3 + 42 = 45.

Explanation:
In the above-given question,
given that,
3 + 42 = 45.
42 + 1 = 43.
43 + 1 = 44.
44 + 1 = 45.
3 + 42 = 45.

Question 22.
Assessment Practice Use the hundred chart. Which equations show the correct sum for 50 + 8? Choose two that apply.
8 + 50 = 85
50 + 8 = 13
8 + 50 = 58
50 + 8 = 58

Options B and D are correct.

Explanation:
In the above-given question,
given that,
50 + 8 = 58.
8 + 50 = 58.
so options B and D are correct.

### Lesson 10.4 Add Tens and Ones Using an Open Number LineName

Solve & Share

Use the open number lines to find the sums.
43 + 6 = ? 5+ 19 = ? 10+ 32 = ?

Visual Learning Bridge

Convince Me!
Think about the problem 20 + 17. Would it be easier to start with 20 or 17 on the number line to solve the problem?

Guided Practice

Question 1.

37 + 30 = 67.

Explanation:
In the above-given question,
given that,
37 + 30 = 67.
37 + 10 = 47.
47 + 10 = 57.
57 + 10 = 67.

Question 2.

26 + 50 = 76.

Explanation:
In the above-given question,
given that,
26 + 50 = 76.
26 + 10 = 36.
36 + 10 = 46.
46 + 10 = 56.
56 + 10 = 66.
66 + 10 = 76.

Question 3.

11 + 8 = ___

11 + 8 = 19.

Explanation:
In the above-given question,
given that,
11 + 8 = 19.
11 + 1 = 12.
12 + 1 = 13.
13 + 1 = 14.
14 + 1 = 15.
15 + 1 = 16.
16 + 1 = 17.
17 + 1 = 18.
18 + 1 = 19.

Question 4.

40 + 16 = ___

40 + 16 = 56.

Explanation:
In the above-given question,
given that,
40 + 16 = 56.
40 + 10 = 50.
50 + 1 = 51.
51 + 1 = 52.
52 + 1 = 53.
53 + 1 = 54.
54 + 1 = 55.
55 + 1 = 56.

Question 5.

48 + 20 = ___

48 + 20 = 68.

Explanation:
In the above-given question,
given that,
48 + 20 = 68.
48 + 10 = 58.
58 + 10 = 68.
so 48 + 20 = 68.

Question 6.

22 + 7 = ___

22 + 7 = 9.

Explanation:
In the above-given question,
given that,
22 + 7 = 29.
22 + 1 = 23.
23 + 1 = 24.
24 + 1 = 25.
25 + 1 = 26.
26 + 1 = 27.
27 + 1 = 28.
28 + 1 = 29.

Question 7.
Higher Order Thinking Write an addition equation using a two-digit and one-digit number. Then solve by showing your work on the number line.

10 + 10 = 20.

Explanation:
In the above-given question,
given that,
10 + 10 = 20.
1 + 1 = 2.
2 + 1 = 3.
3 + 1 = 4.
4 + 1 = 5.
5 + 1 = 6.
6 + 1 = 7.
7 + 1 = 8.
8 + 1 = 9.
9 + 1 = 10.
10 + 10 = 20.

Problem Solving

Solve the problems below.

Question 8.
Use Tools Danny writes 20 pages of his paper on Monday. He writes 32 pages on Tuesday. How many pages did Danny write in all? Use the number line to solve.

20 + 32 = ___ ___ pages

The number of pages did Danny write in all = 52.

Explanation:
In the above-given question,
given that,
Danny writes 20 pages of his paper on Monday.
He writes 32 pages on Tuesday.
20 + 32 = 52.
so the number of pages did Danny write in all = 52.

Question 9.
Use Tools Last year, Leah watched 41 movies. This year, she has watched 30 movies. How many movies has Leah watched in all? Use the number line to solve.

41 + 30 = ___ ___ movies.

The number of movies has Leah watched in all = 71.

Explanation:
In the above-given question,
given that,
Last year, Leah watched 41 movies.
this year, she has watched 30 movies.
41 + 30 = 71.
so the number of movies has Leah watched in all = 71.

Question 10.
Higher Order Thinking Explain how you would solve 57 + 7 on a number line.

57 + 7 = 64.

Explanation:
In the above-given question,
given that,
57 + 7 = 64.
57 + 1 = 58.
58 + 1 = 59.
59 + 1 = 60.
60 + 1 = 61.
61 + 1 = 62.
62 + 1 = 63.
63 + 1 = 64.

Question 11.
Assessment Practice

60 + 26 = ___

60 + 26 = 86.

Explanation:
In the above-given question,
given that,
26 + 10 = 36.
36 + 10 = 46.
46 + 10 = 56.
56 + 10 = 66.
66 + 10 = 76.
76 + 10 = 86.

### Lesson 10.5 Add Tens and Ones Using Models

Solve & Share

Maddy has 50 stickers. Jill gives Maddy 5 more stickers. Use place-value blocks to show how many stickers Maddy has now. Then use numbers and pictures to show your work.

The number of stickers Maddy has now = 60.

Explanation:
In the above-given question,
given that,
Jill gives Maddy 5 more stickers.
50 + 5 = 60.
so the number of stickers Maddy has now = 60.

Visual Learning Bridge

Convince Me!
Could you count on by 10s to add 21 + 20?

21 + 20 = 41.

Explanation:
In the above-given question,
given that,
21 + 20 = 41.
21 + 10 = 31.
31 + 10 = 41.

Guided Practice
Use blocks to add. Then draw what you did.

Question 1.

24 + 4 = 28.

Explanation:
In the above-given question,
given that,
24 + 4 = 28.
24 + 1 = 25.
25 + 1 = 26.
26 + 1 = 27.
27 + 1 = 28.

Question 2.
16 + 30 = __

16 + 30 = 46.

Explanation:
In the above-given question,
given that,
16 + 30 = 46.
16 + 10 = 26.
26 + 10 = 36.
36 + 10 = 46.

Question 3.
32 + 20 = ___

32 + 20 = 52.

Explanation:
In the above-given question,
given that,
32 + 20 = 52.
32 + 10 = 42.
42 + 10 = 52.
32 + 20 = 52.

Question 4.
33 + 6 = ___

33 + 6 = 39.

Explanation:
In the above-given question,
given that,
33 + 6 = 39.
33 + 1 = 34.
34 + 1 = 35.
35 + 1 = 36.
36 + 1 = 37.
37 + 1 = 38.
38 + 1 = 39.

Independent Practice

Question 5.
37 + 2 = ___

37 + 2 = 39.

Explanation:
In the above-given question,
given that,
37 + 2 = 39.
37 + 1 = 38.
38 + 1 = 39.
so 37 + 2 = 39.

Question 6.
21 + 40 = ___

21 + 40 = 61.

Explanation:
In the above-given question,
given that,
21 + 40 = 61.
21 + 10 = 31.
31 + 10 = 41.
41 + 10 = 51.
51 + 10 = 61.

Question 7.
42 + 10 = ___

42 + 10 = 52.

Explanation:
In the above-given question,
given that,
42 + 10 = 52.
42 + 1 = 43.
43 + 1 = 44.
44 + 1 = 45.
45 + 1 = 46.
46 + 1 = 47.
47 + 1 = 48.
48 + 1 = 49.
49 + 1 = 50.
50 + 1 = 51.
51 + 1 = 52.

Question 8.
4 + 33 = ___

4 + 33 = 37.

Explanation:
In the above-given question,
given that,
33 + 4 = 37.
33 + 1 = 34.
34 + 1 = 35.
35 + 1 = 36.
36 + 1 = 37.

Question 9.
50 + 14 = ___

50 + 14 = 64.

Explanation:
In the above-given question,
given that,
14 + 50 = 64.
14 + 10 = 24.
24 + 10 = 34.
34 + 10 = 44.
44 + 10 = 54.
54 + 10 = 64.

Question 10.
Algebra Write the missing numbers. Then write the last addition problem in the pattern.

40 + 5 = 45.
40 + 6 = 46.
40 + 7 = 47.
40 + 8 = 48.
40 + 9 = 49.

Explanation:
In the above-given question,
given that,
40 + 5 = 45.
45 + 1 = 46.
46 + 1 = 47.
47 + 1 = 48.
48 + 1 = 49.

Problem Solving

Write an equation to solve each problem below. Use blocks to help if needed.

Question 11.
Model Jamal has 32 coins in his piggy bank. Jamal’s dad gives him 4 more coins. How many coins does Jamal have now?
___ + ___ = ___
__ coins

The number of coins did Jamal has now = 36.

Explanation:
In the above-given question,
given that,
Jamal has 32 coins in his piggy bank.
Jamal’s dad gives him 4 more coins.
32 + 4 = 36.
so the number of coins did Jamal have now = 36.

Question 12.
Model Julie sells 18 muffins on Monday. She sells 20 muffins on Friday. How many muffins did Julie sell in all?
___ + __ = ___
___ muffins

The number of muffins did Julie sell in all = 38.

Explanation:
In the above-given question,
given that,
Julie sells 18 muffins on Monday.
She sells 20 muffins on Friday.
18 + 20 = 38.
so the number of muffins did Julie sell in all = 38.

Question 13.
Higher Order Thinking Jake has 9 marbles. He gets some more marbles. Now Jake has 79 marbles. How many marbles did Jake get? Draw a picture to solve.

The number of marbles did Jake get = 70.

Explanation:
In the above-given question,
given that,
Jake has 9 marbles.
He gets some more marbles.
Now Jake has 79 marbles.
79 – 9 = 70.
so the number of marbles did Jake get = 70.

Question 14.
Assessment Practice Which is the sum for 40 + 37?
A 47
B 57
C 67
D 77

Option D is correct.

Explanation:
In the above-given question,
given that,
40 + 37 = 57.
37 + 10 = 47.
47 + 10 = 57.
57 + 10 = 67.
67 + 10 = 77.
so option D is correct.

### Lesson 10.6 Make a Ten to Add

Solve & Share

What strategy can you use to find 8 + 5?

Visual Learning Bridge

Convince Me!
When you add two numbers, how do you know if you can make a 10?

Guided Practice
Draw blocks and make a 10 to add.

Question 1.
Find 37 + 7.

37 + 7 = 44.

Explanation:
In the above-given question,
given that,
37 + 3 = 40.
7 = 3 + 4.
40 + 4 = 44.
37 + 7 = 44.

Independent Practice

Draw blocks and make a 10 to add.

Question 2.
17 + 7
Think: 17 + ___ = 20
So, break apart 7 into ___ + ___.
20 + ___ = ___
So, 17 + 7 = ___

17 + 7 = 24.

Explanation:
In the above-given question,
given that,
17 + 3 = 20.
7 = 3 + 4.
20 + 4 = 24.
17 + 7 = 24.

Question 3.
38 +4
Think: 38 + ___ = 40
So, break apart 4 into __ + ___
40 + ___ = ___
So, 38 + 4 = __

38 + 4 = 42.

Explanation:
In the above-given question,
given that,
38 + 2 = 40.
4 = 2 + 2.
40 + 2 = 42.
38 + 4 = 42.

Question 4.
42 + 8 = ___

42 + 8 = 50.

Explanation:
In the above-given question,
given that,
30 + 6 = 36.
6 = 3 + 3.
36 + 3 = 39.
39 + 11 = 50.

Question 5.
29 +5 = ___

29 + 5 = 34.

Explanation:
In the above-given question,
given that,
25 + 4 = 29.
4 = 2 + 2.
29 + 2 = 31.
31 + 2 = 34.

Algebra Write each missing number. Use place-value blocks if you need to.

Question 6.
23 + = 32

The missing number is 9.

Explanation:
In the above-given question,
given that,
23 + x = 32.
32 – 23 = x.
x = 9.
so the missing number is 9.

Question 7.
35 + = 40

35 + 5 = 40.

Explanation:
In the above-given question,
given that,
35 + x = 40.
x = 40 – 35.
x = 5.
so the missing number is 5.

Problem Solving

Solve each problem below.

Question 8.
Model Jamie has 28 cards. His sister gives him 6 more cards. How many cards does Jamie have now? Draw blocks to show your work.
__ cards

The number of cards does Jamie has now = 34.

Explanation:
In the above-given question,
given that,
Jamie has 28 cards.
His sister gives him 6 more cards.
28 + 6 = 34.
so the number of cards does Jamie has now = 34.

Question 9.
Model Lisa knits 15 scarves. Then she knits 8 more. How many scarves does Lisa knit in all? Draw blocks to show your work.
cards
___ scarves

The number of scarves does Lisa knit in all = 23.

Explanation:
In the above-given question,
given that,
Lisa knits 15 scarves.
Then she knits 8 more.
15 + 8 = 23.
so the number of scarves does Lisa knit in all = 23.

Question 10.
Higher Order Thinking Explain how to find 19 + 6. Use equations to show your thinking.

19 + 6 = 25.

Explanation:
In the above-given question,
given that,
19 + 1 = 20.
20 + 1 = 21.
21 + 1 = 22.
22 + 1 = 23.
23 + 1 = 24.
24 + 1 = 25.

Question 11.
Assessment Practice Explain how to use the make a 10 strategy to find 37 + 5.

37 + 5 = 42.

Explanation:
In the above-given question,
given that,
37 + 1 = 38.
38 + 1 = 39.
39 + 1 = 40.
40 + 1 = 42.

Lesson 10.7 Add Using Place Value

Solve & Share

Grace is solving 35 + 8. First she adds 35 + 5 = 40. What should she do next to find the answer? Draw a model to explain.

Visual Learning Bridge

Convince Me!
Do you need to make a 10 to add 23 + 15? How do you know?

Guided Practice

Question 1.
Find 36 + 24.
6 + 4 = 10
30 + 20 = ___
So, 36 + 24 = ___

36 + 24 = 60.

Explanation:
In the above-given question,
given that,
6 + 4 = 10.
30 + 20 = 50.
36 + 24 = 60.
50 + 10 = 60.

Question 2.
Find 19 + 25.
9 + 5 = 14
10 + 20 = 30
So, 19 + 25 = ___

19 + 25 = 44.

Explanation:
In the above-given question,
given that,
9 + 5 = 14.
10 + 20 = 30.
30 + 14 = 44.
19 + 25 = 44.

Independent Practice

Add. Draw blocks or an open number line to help./

Question 3.
Find 19 + 42.
9 + 2 = ___
10 + 40 = ___
19 + 42 = ___

19 + 42 = 61.

Explanation:
In the above-given question,
given that,
9 + 2 = 11.
10 + 40 = 50.
19 + 42 = 61.
50 + 11 = 61.

Question 4.
Find 27 + 25.
7 + 5 = ___
20 + 20 = ___
27 + 25 = ___

27 + 25 = 32.

Explanation:
In the above-given question,
given that,
7 + 5 = 12.
20 + 20 = 40.
27 + 25 = 32.

Add. You can draw blocks or an open number line to help.

Question 5.
37 + 33 = ___

37 + 33 = 70.

Explanation:
In the above-given question,
given that,
7 + 3 = 10.
30 + 30 = 60.
60 + 10 = 70.
37 + 33 = 70.

Question 6.
28 + 44 = ___

28 + 44 = 72.

Explanation:
In the above-given question,
given that,
8 + 4 = 12.
20 + 40 = 60.
60 + 12 = 72.
28 + 44 = 72.

Question 7.
25 + 26 = ___

25 + 26 = 51.

Explanation:
In the above-given question,
given that,
5 + 6 = 11.
20 + 20 = 40.
40 + 11 = 51.
25 + 26 = 51.

Question 8.
56 + 33 = ___

56 + 33 = 89.

Explanation:
In the above-given question,
given that,
6 + 3 = 9.
50 + 30 = 80.
80 + 9 = 89.
56 + 33 = 89.

Problem Solving

Solve. You can draw blocks or an open number line to help you.

Question 9.
Reasoning Sara mows 15 lawns. Bill mows 12 lawns. How many lawns did they mow in all? Write an addition equation to show the problem.
__ lawns

The number of lawns did they mow in all = 27.

Explanation:
In the above-given question,
given that,
Sara mows 15 lawns.
Bill mows 12 lawns.
15 + 12 = 27.
so the number of lawns did they mow in all = 27.

Question 10.
Reasoning Jon reads 24 pages. Then he reads 27 more pages. How many pages does he read in all? Write an addition equation to show the problem.
___ pages

The number of pages does he read in all = 51.

Explanation:
In the above-given question,
given that,
Then he reads 27 more pages.
24 + 27 = 51.
so the number of pages does he read in all = 51.

Question 11.
Higher Order Thinking Explain how to find 27 + 15 by adding the tens first. Use equations to show your thinking.

27 + 15 = 42.

Explanation:
In the above-given question,
given that,
27 + 15 = 42.
7 + 5 = 12.
20 + 10 = 30.
30 + 12 = 42.

Question 12.
Assessment Practice For which addition equations can you make a 10 to add? Choose two that apply.
12 + 29 = ?
61 +26 = ?
33 + 35 = ?
34 + 18 = ?

Option A is correct.

Explanation:
In the above-given question,
given that,
12 + 29 = 41.
9 + 2 = 11.
10 + 20 = 30.
30 + 11 = 41.

### Lesson 10.8 Practice Adding Using Strategies

Solve & Share

A puzzle has 59 green pieces and 25 orange pieces. Solve 59 + 25 to find how many pieces in all. Use any of the strategies you have learned.

59 + 25 = 84.

Explanation:
In the above-given question,
given that,
9 + 5 = 14.
50 + 20 = 70.
70 + 14 = 84.

Visual Learning Bridge

Convince Me!
Why can you use different strategies to solve the same problem?

Guided Practice

Find each sum. Solve any way you choose. Draw or explain what you did.

Question 1.
37 + 24 = 61

37 + 24 = 61.

Explanation:
In the above-given question,
given that,
37 + 24 = 61.
7 + 4 = 11.
30 + 20 = 50.
50 + 11 = 61.
so 37 + 24 = 61.

Question 2.
48 + 10 = ___

48 + 10 = 58.

Explanation:
In the above-given question,
given that,
48 + 10 = 58.
8 + 0 = 8.
40 + 10 = 50.
50 + 8 = 58.

Independent Practice

Find each sum. Solve any way you choose. Draw or explain what you did.

Question 3.

27 + 9 = 36.

Explanation:
In the above-given question,
given that,
9 + 7 = 16.
20 + 0 = 20.
20 + 16 = 36.

Question 4.

50 + 23 = 73.

Explanation:
In the above-given question,
given that,
0 + 3 = 3.
50 + 20 = 70.
70 + 3 = 73.

Question 5.

32 + 28 = 60.

Explanation:
In the above-given question,
given that,
32 + 28 = 60.
8 + 2 = 10.
30 + 20 = 50.
50 + 10 = 60.
32 + 28 = 60.

Question 6.

62 + 19 = 81.

Explanation:
In the above-given question,
given that,
62 + 19 = 81.
60 + 10 = 70.
2 + 9 = 11.
70 + 11 = 81.
62 + 19 = 81.

Problem Solving

Find each sum. Solve any way you choose.

Question 7.
Reasoning Lilly makes necklaces. She has 43 blue beads. She has 20 pink beads. How many beads does Lilly have in all?

The number of beads does Lilly has in all = 63.

Explanation:
In the above-given question,
given that,
Lilly makes necklaces.
43 + 20 = 63.
so  the number of beads does Lilly have in all = 63.

Question 8.
Reasoning Jay has a hat collection. He has 27 hats from football teams. He has 33 hats from baseball teams. How many hats does Jay have in all?
___ hats

The number of hats does Jay has in all = 60.

Explanation:
In the above-given question,
given that,
Jay has a hat collection.
He has 27 hats from football teams.
He has 33 hats from baseball teams.
27 + 33 = 60.
so the number of hats does Jay has in all = 60.

Question 9.
Higher Order Thinking Connie’s soccer team has a bake sale. The team sells 18 banana muffins and 24 oat muffins. They sell 12 granola bars. How many muffins did Connie’s team sell? Draw a picture and write an equation to show your work.
___ muffins

The number of muffins did Connie’s team sell = 54 muffins.

Explanation:
In the above-given question,
given that,
Connie’s soccer team has a bake sale.
The team sells 18 banana muffins and 24 oat muffins.
They sell 12 granola bars.
18 + 24 + 12.
18 + 24 = 42.
42 + 12 = 54.
so the number of muffins did Connie’s team sell = 54 muffins.

Question 10.
Assessment Practice Garret uses place-value blocks to show 53 + 18. Which of the following model this problem? Choose two that apply.

Option B is correct.

Explanation:
In the above-given question,
given that,
53 + 18 = 71.
3 + 8 = 11.
50 + 10 = 60.
60 + 11 = 71.
so option B is correct.

### Lesson 10.9 Model with Math

Solve & Share
Pam has 13 buttons. Julie gives her some more. Now Pam as 30 buttons. Use blocks or a number line to figure out how many buttons Julie gave Pam.

Thinking Habits
How can I use numbers and symbols to solve this problem? How can I use the math I know to show this problem?

Visual Learning Bridge

Convince Me!
If Miko has 23 green marbles and 30 blue marbles, how many marbles does he have in all? Draw a picture to solve the problem.

Guided Practice
Use drawings to show and solve the problem. Then write the equation.

Question 1.
Ellen has 27 stickers. Her brother gives her 26 stickers. How many stickers does Ellen have in all?
___ + ___= ___

27 + 26 = 53.

Explanation:
In the above-given question,
given that,
Ellen has 27 stickers.
Her brother gives her 26 stickers.
27 + 26 = 53.

Independent Practice

Use drawings to show and solve the problem. Then write the equation.

Question 2.
Barry has 12 red cars. He has 14 blue cars. How many cars does Barry have in all?
___ + ___ = ___ cars

The number of cars does Barry have in all = 26.

Explanation:
In the above-given question,
given that,
Barry has 12 red cars.
He has 14 blue cars.
12 + 14 = 26.
so the number of cars does Barry have in all = 26.

Question 3.
Amy picks 18 roses. Roger picks 36 tulips. How many flowers do Amy and Roger pick in all?
___ + ___ = ___ flowers

The number of flowers do Amy and Roger pick in all = 54.

Explanation:
In the above-given question,
given that,
Amy picks 18 roses.
Roger picks 36 tulips.
18 + 36 = 54.
so the number of flowers do Amy and Roger pick in all = 54.

Question 4.
There are 16 apples in the bowl. George buys 15 more apples. How many apples are there in all?
__ + ___ = __ apples

The number of apples is there in all = 31.

Explanation:
In the above-given question,
given that,
There are 16 apples in the bowl.
16 + 15 = 31.
so the number of apples are there in all = 31.

Problem Solving

Stamp Collection
Manuel, Matt, and Jessica each have their own stamp collection.

Question 5.
Model Manuel has 18 stamps. Matt gives Manuel 30 stamps. Now, how many stamps does Manuel have in all? Draw a picture to show the problem.

The number of stamps does Manuel has in all = 48.

Explanation:
In the above-given question,
given that,
Manuel has 18 stamps.
Matt gives Manuel 30 stamps.
18 + 30 = 48.
so the number of stamps does Manuel has in all = 48.

Question 6.
Model Write an equation that matches the story.

The number of stamps does Manuel has in all = 48.

Explanation:
In the above-given question,
given that,
Manuel has 18 stamps.
Matt gives Manuel 30 stamps.
18 + 30 = 48.
so the number of stamps does Manuel has in all = 48.

Question 7.
Explain Matt has 24 red stamps. He asks Jessica for enough red stamps to make 50 red stamps. Jessica gives him 25 red stamps. Did Jessica give Matt enough red stamps? Explain how you know using words or pictures.

Can you make a 10? Why or why not.

Jessica did not give Matt enough red stamps.

Explanation:
In the above-given question,
given that,
Matt has 24 red stamps.
He asks Jessica for enough red stamps to make 50 red stamps.
Jessica gives him 25 red stamps.
24 + 26 = 50.
no, Jessica did not give Matt enough red stamps.

### Topic 10 Fluency Practice

Color these sums and differences. Leave the rest white.

Topic 10 Vocabulary Review

Understand Vocabulary

Question 1.
Use the models to add the tens.

___ tens + ___ tens = ___ tens

3 tens + 2 tens = 50.

Explanation:
In the above-given question,
given that,
3 tens = 30.
2 tens = 20.
30 + 20 = 50.

Question 2.
Use the models to add the tens.

___ tens + ___ tens = ___ tens

2 tens + 4 tens = 6 tens.

Explanation:
In the above-given question,
given that,
2 tens + 4 tens.
2 tens = 20.
4 tens = 40.
20 + 40 = 60.

Question 3.
Find 19 + 12.
Add the ones. 9 + 2 = ___
Then add the tens. 10 + 10 = ___
Draw blocks to help. 19 + 12 = ___

19 + 12 = 31.

Explanation:
In the above-given question,
given that,
9 + 2 = 11.
10 + 10 = 20.
19 + 12 = 31.

Use Vocabulary in Writing

Question 4.
Solve 20 + 6 using an open number line. Explain how you solved it using terms from the Word List.

20 + 6 = 26.

Explanation:
In the above-given question,
given that,
20 + 1 = 21.
21 + 1 = 22.
22 + 1 = 23.
23 + 1 = 24.
24 + 1 = 25.
25 + 1 = 26.

### Topic 10 Reteaching

Set A

You can add groups of 10.

Write the numbers to complete each equation.

Question 1.

4 tens + 1 ten = 5 tens.

Explanation:
In the above-given question,
given that,
4 tens + 1 ten = 5 tens.
4 tens = 40.
1 tens = 10.
40 + 10 = 50.

Question 2.

3 tens + 3 ten = 6 tens.

Explanation:
In the above-given question,
given that,
3 tens + 3 tens = 6 tens.
3 tens = 30.
3 tens = 30.
30 + 30 = 60.

Set B

You can also use mental math to add 10. When you add 10, the tens digit goes up by 1. The ones digit stays the same.

2 tens + 1 ten = 3 tens.
3 tens + 4 ones = 34.

Explanation:
In the above-given question,
given that,
2 tens + 1 ten = 3 tens.
3 tens = 30.
4 ones = 4.
30 + 4 = 34.

Use mental math to solve the problems below.

Question 3.
36 + 10 = ___

36 + 10 = 46.

Explanation:
In the above-given question,
given that,
6 + 0 = 6.
30 + 10 = 40.
40 + 6 = 46.

Question 4.
53 + 10 = ___

53 + 10 = 63.

Explanation:
In the above-given question,
given that,
3 + 0 = 3.
50 + 10 = 60.
60 + 3 = 63.
so 53 + 10 = 63.

Question 5.
71 + 10 = ___

71 + 10 = 81.

Explanation:
In the above-given question,
given that,
1 + 0 = 1.
70 + 10 = 80.
80 + 1 = 81.
so 71 + 10 = 81.

Set C

You can use part of a hundred chart to add tens and ones.
3+ 40 = ?

Use the part of the hundred chart to add tens and ones.

Question 6.
4 + 50 = ___

4 + 50 = 54.

Explanation:
In the above-given question,
given that,
4 + 0 = 4.
50 + 0 = 50.
50 + 4 = 54.

Question 7.
8 + 30 = ___

8 + 30 = 38.

Explanation:
In the above-given question,
given that,
8 + 0 = 8.
30 + 0 = 30.
30 + 8 = 38.

Set D

You can use an open number line to add.

Use an open number line to add.

Question 8.

11 + 6 = ___

11 + 6 = 17.

Explanation:
In the above-given question,
given that,
10 + 7 = 17.
11 + 6 = 17.

Set E

You can use blocks to add tens to a number.

Question 9.
44 + 30 = ___

4 + 0 = 4.

Explanation:
In the above-given question,
given that,
40 + 30 = 70.
4 tens = 40.
3 tens = 30.
40 + 30 = 70.

Question 10.
20 + 5 = ___

20 + 5 = 25.

Explanation:
In the above-given question,
given that,
0 + 5 = 5.
20 + 0 = 20.
20 + 5 = 25.

Question 11.
30 + 28 = ___

30 + 28 = 58.

Explanation:
In the above-given question,
given that,
0 + 8 = 8.
30 + 20 = 50.
50 + 8 = 58.
30 + 28 = 58.

Question 12.
19 + 60 = ___

19 + 60 = 79.

Explanation:
In the above-given question,
given that,
9 + 0 = 9.
10 + 60 = 70.
70 + 9 = 79.
19 + 60 = 79.

Set F

Sometimes you can make 10 when you add.

Draw blocks and make a 10 to add.

Question 13.
33 + 9

Think: 33 + __ = 40
So, break apart 9 into ___ + ___.
40 + __ = ___
So, 33 + 9 = ___

33 + 9 = 42.

Explanation:
In the above-given question,
given that,
33 + 7 = 40.
9 = 5 + 4.
33 + 9 = 42.

Set G

There are 4 tens and 3 ones. 24 + 19 = 43

Question 14.
Find 67 + 16.
7 + 6 = ___
60 + 10 = ___
67 + 16 = ___

67 + 16 = 83.

Explanation:
In the above-given question,
given that,
7 + 6 = 13.
60 + 10 = 70.
67 + 16 = 83.

Set H

Thinking Habits
Model with Math

Can I use a drawing, diagram, table, or graph to model the problem? Can I write an equation to show the problem?

Use drawings to show and solve the problem. Then write the equation.

Question 15.
Sally sees 15 birds. Then she sees 17 more. How many birds did Sally see in all?
___ + ___ = ___

The number of birds did Sally see in all = 32.

Explanation:
In the above-given question,
given that,
Sally sees 15 birds.
Then she sees 17 more.
15 + 17 = 32.
so the number of birds did Sally see in all = 32.

### Topic 10 Assessment Practice

Question 1.
Write an equation that matches the place-value blocks below.

5 tens + 8 ones = 58.

Explanation:
In the above-given question,
given that,
5 tens = 50.
8 ones = 8.
5 tens + 8 ones = 58.

Question 2.
Find the sum. Draw place-value blocks to show how you found it. 50 + 3 = ___

50 + 3 = 53.

Explanation:
In the above-given question,
given that,
0 + 3 = 3.
5 tens = 5 tens.
3 ones = 3.
5 tens + 3 ones = 53.

Question 3.
Find the sum of 16 and 18.
Use words, pictures, or a model to solve. Write the equation.

16 + 18 = 34.

Explanation:
In the above-given question,
given that,
16 + 18 = 34.
6 + 8 = 14.
10 + 10 = 20.
20 + 14 = 34.
16 + 18 = 34.

Question 4.
Which equation matches the place-value blocks shown below? Choose two that apply.

60 + 30 = 90
6 tens + 3 tens = 9 tens
60 + 10 = 70
4 tens + 3 tens = 7 tens
6 tens + 3 ones = 9 ones

Options A and B are correct.

Explanation:
In the above-given question,
given that,
60 + 30 = 90.
6 tens + 3 tens = 9 tens.
so options A and B are correct.

Question 5.
Find the sum of 18 and 11. Explain how you solved the problem. Did you need to make a 10?

The sum of 18 and 11 = 29.

Explanation:
In the above-given question,
given that,
18 + 11 = 29.
10 + 10 = 20.
8 + 1 = 9.
20 + 9 = 29.
so the sum of 18 and 11 = 29.

Question 6.
Solve the problem.
Use place-value blocks if needed. 28 + 13 = Can you make a 10? Explain.
Circle Yes or No.

28 + 13 = 41.

Explanation:
In the above-given question,
given that,
28 + 13 = 41.
20 + 10 = 30.
8 + 3 = 11.
28 + 13 = 41.

Question 7.
Use the part of the hundred chart to add. Choose the possible explanation for how to find 46 + 20.

A. I start at 46 and then move two rows up to get 26. So, 46 + 20 = 26.
B. I start at 46 and then move one row down and four columns to the right to get 60. So, 46 + 20 = 60.
C. I start at 46 and then move two rows down to get 66. So, 46 + 20 = 66.
D. I start at 46 and then move two rows down to get 68. So, 46 + 20 = 68.

Option C is correct.

Explanation:
In the above-given question,
given that,
46 + 20 = 66.
I start at 46 and then move two rows down to get 66.
46 + 20 = 66.
so option C is correct.

Use the part of the hundred chart to solve each problem. What is one way to explain your answer?

Question 8.
10 + 27 = ?
A. 17; I started at 27 and subtracted 1 ten.
B. 28; I started at 27 and added 1 ten.
C. 37; I started at 27 and added 1 ten.
D. 40; I started at 10 and added 3 tens.

Option C is correct.

Explanation:
In the above-given question,
given that,
10 + 27 = 37.
I started at 27 and added 1 ten.
27 + 10 = 37.
so option C is correct.

Question 9.
4 + 35 = ?
A. 95; I started at 35 and added 4 tens.
B. 39; I started at 35 and added 4 ones.
C. 31; I started at 35 and subtracted 4 ones.
D. 12; I started at 32 and subtracted 2 tens.

Option B is correct.

Explanation:
In the above-given question,
given that,
4 + 35 = 39.
I started at 35.
added the 4 ones to 35.
35 + 4 = 39.

Use mental math to solve. Then explain how you found your answer.

Question 10.
53 + 10 = ___

53 + 10 = 63.

Explanation:
In the above-given question,
given that,
3 + 0 = 3.
50 + 10 = 60.
60 + 3 = 63.
53 + 10 = 63.

Question 11.
48 + 10 = ___

48 + 10 = 58.

Explanation:
In the above-given question,
given that,
48 + 10 = 58.
40 + 10 = 50.
8 + 0 = 8.
50 + 8 = 58.
48 + 10 = 58.

Question 12.
64 + 10 = ___

64 + 10 = 74.

Explanation:
In the above-given question,
given that,
64 + 10 = 74.
4 + 0 = 4.
60 + 10 = 70.
70 + 4 = 74.

Find the correct number to complete each equation.

Question 13.
20 + 70 = ___

20 + 70 = 90.

Explanation:
In the above-given question,
given that,
2 tens + 7 tens.
2 tens = 20.
7 tens = 70.
20 + 70 = 90.

Question 14.
30 + ___ = 60

30 + 30 = 60.

Explanation:
In the above-given question,
given that,
3 tens =30.
3 tens =30

30 + 30 = 60.

Question 15.
__ + 20 = 40

20 + 20 =40.

Explanation:
In the above-given question,
given that,
2 tens = 20.
2 tens =20.

20 + 20 = 40.

Question 16.
Use the open number line to find 40 + 23. Show your work.

40 + 23 = 63.

Explanation:
In the above-given question,
given that,
23 + 10 = 33.
33 + 10 = 43.
43 + 10 = 53.
53 + 10 = 63.

Question 17.
Find 43 + 8. Do the models correctly show the sum? Explain how you know.

43 + 8 = 51.

Explanation:
In the above-given question,
given that,
8 + 3 = 11.
40 + 0 = 40.
40 + 11 = 51.
43 + 8 = 51.

Solve each problem. Can you make a 10? Use place-value blocks if needed.

42 + 37 = 79.
16 + 35 = 51.
14 + 16 = 30.

Explanation:
In the above-given question,
given that,
40 + 2 = 42.
30 + 7 = 37.
42 + 37 = 79.

10 + 6 = 16.
30 + 5 = 35.
16 + 35 = 51.

10 + 4 = 14.
10 + 6 = 16.
14 + 16 = 30.

Pet Survey

Maria asked other students what kind of pet they have. She made this chart.

Question 1.
How many Fish and Cats in all? Use the open number line to solve.

___ fish and cats

The number of fish and cats = 57.

Explanation:
In the above-given question,
given that,
there are 27 fish in the chart.
there are 30 cats in the chart.
27 + 30 = 57.
so the number of fish and cats = 57.

Question 2.
How many Dogs and Birds in all? Use the hundred chart to add.

__ + __ = ___
__ dogs and birds

The number of dogs and birds = 47.

Explanation:
In the above-given question,
given that,
there are 8 birds in the chart.
there are 39 dogs in the chart.
8 + 39 = 47.
so the number of dogs and birds = 47.

Question 3.
Use place-value blocks to solve. Draw the blocks you used.

The number of students did she ask on both days = 35.

Explanation:
In the above-given question,
given that,
18 + 17 = 35.
so the number of students did she ask on both days = 35.

Question 4.
Maria adds other pets to her chart. 19 students in first grade have a rabbit. 24 students in second grade have a rabbit. How many students in all have rabbits?
Part A
Part B
Write an equation that matches the story.