We included HMH Into Math Grade 1 Answer Key PDF Module 12 Lesson 3 Add or Subtract Tens to make students experts in learning maths.

I Can add and subtract multiples of ten. A squirrel has ____________ acorns.
Then she has ____________ acorns.
Now she has ____________ acorns. Read the following: A squirrel has 50 acorns. She gathers 30 more acorns. Then she buries 60 acorns. How many acorns does the squirrel have now? Allow children to choose tools to solve the problem, including 10-cube trains. Explanation:
A squirrel has 50 acorns
She gathers 30 more acorns
I counted by 10’s in the hundreds chart to show the problem
I moved down the rows to add tens
50 + 30 = 80
Then she buries 60 acorns
I counted by 10’s in the hundreds chart to show the problem
I moved up the rows to subtract tens
80 – 60 = 20
The squirrel has 20 acorns now.

Build Understanding

Question 1.
How can you use a hundred chart to solve these problems? A. One class collects empty cans. On Monday, they collect 30 cans. On Tuesday, they collect 40 cans.
How many cans does the class collect?
___________ cans Explanation:
One class collects empty cans
On Monday, they collect 30 cans
On Tuesday, they collect 40 cans
I counted by 10’s in the hundreds chart to show the problem
I moved down the rows to add tens
40 + 30 = 70
So, The class collected 70 cans.

B. Another class wants to collect 50 bottles. The class has 20 bottles What does the class need to do? Explain. Explanation:
Another class wants to collect 50 bottles
The class has 20 bottles
I counted by 10’s in the hundreds chart to show the problem
I moved down the rows to add tens
20 + 30 = 50
50 – 20 = 30
So, The class needs to collect 30 more bottles.

Turn and Talk Describe how to write equations for the problems on this page.

Step It Out

Question 1.
Use the hundred chart to solve these problems. THINK: I can move up or down rows to add and subtract tens.
A. 90 – 30 = ________
I counted by 10’s in the hundreds chart
90 – 30 = 60
I moved rows up to show to subtract tens

B. _________ + 20 = 30
I counted by 10’s in the hundreds chart to show the problem
10 + 20 = 30
I moved the rows up to subtract tens

C. _________ = 40 + 40
I counted by 10’s in the hundreds chart
80 = 40 + 40
I moved down the rows to add tens

D. 30 = 80 – _________
I counted by 10’s in the hundreds chart
30 = 80 -50
I moved up the rows to subtract tens.

Check Understanding

Solve. Write an equation to show the problem.

Question 1.
There are 20 fish in a tank 50 more fish are put in the tank. How many fish are in the tank now? Equation: ___________
_________ fish Explanation:
There are 20 fish in a tank 50 more fish are put in the tank
I counted by 10’s in the hundreds chart to show the problem
I moved down the rows to add tens
20 + 50 = 70
There are 70 fishes in the tank now.

Question 2.
50 + _________ = 80
50 + 30 = 80

Explanation:
Start at 50, Count up by 10’s till 80
I counted 3 tens
So, 50 + 30 = 80

Question 3.
__________ = 90 – 20
70 = 90 – 20

Explanation:
Start at 90, Count back by 10’s
Count 2 tens back
90 before 80, 70
So, 90 – 20 = 70.

Model with Mathematics Write an addition or subtraction equation to solve.

Question 4.
Dan has 20 jars. He finds more jars. Now he has 60 jars. How many jars does Dan find?
Equation: __________
__________ jars Explanation:
Dan has 20 jars
He finds more jars
Now he has 60 jars
I counted by 10’s in the hundreds chart to show the problem
Start at 20
I moved down the rows to add tens till 60
I counted 4 tens more
So, 20 + 40 = 60
Dan finds 40 more jars.

Question 5.
Rachel has 60 cups. Nate gives her 10 cups. How many cups does Rachel have now?
Equation: ___________
_________ cups Explanation:
Rachel has 60 cups
Nate gives her 10 cups
I counted by 10’s in the hundreds chart to show the problem
I moved down the rows to add tens
60 + 10 = 70
So, Rachel have 70 cups now.

Question 6.
Seeds form in flowers. Seeds grow into new plants. Trisha has 70 flower seeds. She plants 30 seeds. How many seeds does she still need to plant? Equation: ____________
_________ seeds Explanation:
Seeds form in flowers. Seeds grow into new plants
Trisha has 70 flower seeds
She plants 30 seeds
I counted by 10’s in the hundreds chart to show the problem
Start at 30
I moved down the rows to add tens till 70
I counted 4 tens more
30 + 40 = 70
So, 70 – 30 = 40
Trisha needs 40 more seeds to plant.

I’m in a Learning Mindset!

How am I managing my learning with adding and subtracting tens?