Using Fact Families to Help Subtract

Using Fact Families to Help Subtract

I can use fact families to help me solve subtraction word problems

Read and try to solve the word problem

There are 15 birds swimming in a pond. Then 9 birds fly away. How many birds are left?

Lets Read the problem again; think to yourself.

What is my number sentence?

There are 15 birds swimming in a pond. Then 9 birds fly away. How many birds are left?

Let create a number sentence in your notebook.

There are 15 birds swimming in a pond. Then 9 birds fly away.

Now Lets make a fact family

We know that we have 15 total birds and 9 flu away. We need to find out How many birds are left by using a fact family.

Fact Family Questions. Think about it!

*How to do think a fact family is like a real family?

* What do you see in this fact family?

Multiple Select

Click on all the problems that is in this fact family.

• 9+?=15

• ?+9=15

• 15-9=?

• 15-?=9

• 7+2=?

Multiple Choice

Which Fact Family number sentence can help you solve the problem? How many birds left?

• 9+?=15

• ?+9=15

• 15-?=9

• 15-9=?

Multiple Choice

Now solve the problem: There are 15 birds swimming in a pond. Then 9 fly away. How many birds are left?

• 7

• 6

• 10

• 3

Explore another way to understand solving subtraction problem in your head

There are 15 birds swimming in a pond. Then 9 birds fly away. How many birds are left?

Model It

Use a facts family to help solve the problem.

Find the difference 15-9

Use the numbond to write a fact family.

Multiple Select

Click on all the fact family problems for 15-9=?

• 9+?=15

• 15-?=9

• ?+9=15

• 15-9=?

• 15-7=?