# Into Math Grade 1 Module 13 Lesson 1 Answer Key Use a Hundred Chart to Show Two-Digit Addition and Subtraction

We included HMH Into Math Grade 1 Answer Key PDF Module 13 Lesson 1 Use a Hundred Chart to Show Two-Digit Addition and Subtraction to make students experts in learning maths.

## HMH Into Math Grade 1 Module 13 Lesson 1 Answer Key Use a Hundred Chart to Show Two-Digit Addition and Subtraction

I Can use a hundred chart to add or subtract two-digit numbers.

There are _________ birds.
Then _________ more birds come.
Now there are _________ birds in the tree.

Read the following aloud: There are 36 birds in a tree. More birds come. Now there are 56 birds in the tree. How many birds come to the tree? Have children choose tools to solve the problem.

Explanation:
There are 36 birds in a tree
More birds come
Now there are 56 birds in the tree
Start at 36, count on by 10’s till 56
36 after 46, 56
I counted 2 more
2 tens is 20
So, 20 birds came to the tree.

Build Understanding

Question 1.
How can you use the hundred chart to solve these problems?

A. There are 30 frogs in a pond. Some frogs hop away. There are 10 frogs left. How many frogs hop away?

___________ frogs

Explanation:
There are 30 frogs in a pond. Some frogs hop away
There are 10 frogs left
Start at 10, count by 10’s
Count on till 30
10 after 20, 30
I counted 2 more
2 tens is 20
So, 20 frogs hop away.

B. Haley sees 38 sheep in the barn. She sees more sheep in the field. She sees 78 sheep in all. How many sheep does she see in the field?

_________ sheep

Explanation:
Haley sees 38 sheep in the barn
She sees more sheep in the field
She sees 78 sheep in all
Start at 38, count by 10’s
Count on till 78
38 after 48, 48, 68, 78
I counted 4 more
4 tens is 40
So, 40 sheep are in the field.

How did you use the hundred chart to solve the problem? Explain.
I used hundreds chart to solve the problem. I counted on and back by 10’s to find the answer.
I can easily find the next and back tens in the hundreds chart.

Turn and Talk How can you use the hundred chart to subtract?
I can use hundreds chart to subtract.
First mark the number from which i subtract then count back by 1’s or 10’s to subtract the number i need to subtract.
I will reach the answer that is the difference of the numbers.

Step It Out

Question 1.
There are 45 trees in a park. More trees are planted. Now there are 65 trees. How many trees are planted?

45 + _________ = 65
A. Start at the number 45.

B. Use the hundred chart to add.
THINK: I can count on tens to get to 65.
Count on ___________ tens.
_________ tens = _________

C. __________ more trees were planted.
Start at the number 45
I can count on tens to get 65
Count on 2 tens
2 ten = 20
So, 20 more trees were planted.

Check Understanding

Use the hundred chart to solve.

Question 1.
There are 80 bees in a hive. Some bees fly away. There are 50 bees left. How many bees fly away?

__________ bees

Explanation:
There are 80 bees in a hive
Some bees fly away
There are 50 bees left
Start at 50, count on by 10’s till 80
50 after 60, 70, 80
I counted 3 more times
3 tens is 30
So, 30 bees flew away.

Use the hundred chart to solve.

Question 2.
There are 24 flowers on a tree. More flowers bloom. Now there are 34 flowers. How many flowers bloom?

_________ flowers

Explanation:
There are 24 flowers on a tree
More flowers bloom
Now there are 34 flowers
34 – 24 = 10
So, 10 more flowers bloom.

Question 3.
Reason There are 70 flowers on a tree. The wind blows 20 flowers off the tree. How many flowers are on the tree now? Explain your answer.

___________ flowers

Explanation:
There are 70 flowers on a tree
The wind blows 20 flowers off the tree
Start at 70
Count back by 10’s
Count 2 times
70 before 60, 50
I am at 50 now
70 – 20 = 50
So, there are 50 flowers on the tree now.

Question 4.
33 + 30 = __________
33 + 30 = 63

Explanation:
Start at 33
Count by 10’s
Count on 3 more
33 after 43, 53 and 63
I am at 63 now
So, 33 + 30 = 63.

Question 5.
80 – 70 = ___________
80 – 70 = 10

Explanation:
Start at 80
Count by 10’s
Count back 7 times
80 before 70, 60, 50, 40, 30, 20, 10
I am at 10 now
So, 80 – 70 = 10.

Question 6.
60 – 50 = __________
60 – 50 = 10

Explanation:
Start at 60
Count by 10’s
Count back 5 times
60 before 50, 40, 30, 20, 10
I am at 10 now
60 – 50 = 10.

Question 7.
17 + 40 = _____________
17 + 40 = 57

Explanation:
Start at 17
Count by 10’s
Count on 4 more
17 after 27, 37, 47
I am at 57 now
17 + 40 = 57.

I’m in a Learning Mindset!

How did I feel about my learning when I solved Problem 2?