Fish Tank Subtraction: Use an Addition Fact
0 / 12Fish Tank Subtraction: Use an Addition Fact
Solve each subtraction by finding the missing addend.
Find the Missing Number
Use an addition fact to solve each subtraction.
1.
There are 12 fish in the tank. 8 fish are orange. The rest are blue. How many fish are blue?
8 + = 12, so 12 − 8 = blue fish
2.
To find 15 − 9, think 9 + = 15.
3.
To find 11 − 7, think 7 + = 11.
4.
17 − 8 = because 8 + = 17.
5.
Think of an addition fact to help you.
13 − 6 =
Fish Tank Stories
Read each story. Think addition to solve it.
6.
There are 14 snails in the tank. 5 snails are on the glass. The rest are on the rocks. How many snails are on the rocks?
snails are on the rocks.
7.
Ella needs 10 plants for the class fish tank. She has 3 plants. Which addition fact helps her find how many more plants she needs?
8.
Which subtraction can you solve with 6 + 9 = 15?
9.
Match each subtraction to the addition fact that helps you solve it.
10.
There are 19 guppies in the tank. Some guppies swim behind the castle. Now you can see 10 guppies. How many guppies are behind the castle?
guppies are behind the castle.
Check the Answers
Use addition to check each subtraction.
11.
Add to check each answer. Sort each subtraction as correct or not correct.
12.
Leo says, "To find 14 − 8, I think 8 + 6 = 14." Is Leo right? Tell how you know and write the answer to 14 − 8.