Inverse Operations

Vocabulary

100

When you find out how many in all, combined, total or how much altogether what is the operation called?

addition

200

When you find out how many are left, or the difference, what is that operation called?

Subtraction

300

What is the inverse of addition?

Subtraction

400

What is the inverse of multiplication?

Division

500

What is another word for the "opposite" operation?

inverse

Inverse of Addition

100

13 - 8 = 5

What is the inverse of 8 + 5 = 13

200

9+8=17 What is the inverse?

17-8=9 or 17-9=8

300

45+13=? What is the inverse?

58-13=45 or 58-45=13

400

7+6=13.... What is the inverse? a. 6+13=19 b. 6+7=13 c. 13-4=9 d. 13-6=7

d. 13-6=7

500

Which problem would you use to check 35+63=98 a. 63+35=98 b. 98-63=35 c. 98+35=63 d. 98-20=73

b. 98-63=35

Inverse of Subtraction

100

11-6=5

5+6=11 or 6+5=11

200

9-7=2

7+2=9 or 2+7=9

300

83-41=? What is the inverse?

42+41=83 or 41+42=83

400

Which problem is the inverse of 24-15=___ ? a. 24-5=19 b. 9+5= 14 c. 15+9=24 d. 159

c

500

35 + 135 = 170

What is the inverse of 170 - 135?

Inverse Operations

100

Jamie runs 6 laps. Julie runs 5 times as many laps as Jamie. Complete a Bar Model to find how many laps Julie ran. 

Jamie    6

Julie     6 6 6 6 6 

Julie ran 30 laps. 

200

Use the inverse operation to solve 

Billy took 18 photos for the yearbook. That is 3 times as many photos as Ginnie. How many photos did Ginnie take? 

3 x n = 18 

n= 6 

300

sixteen + nine = ____________ What is the inverse operation?

25-9=16 or 25-16=9

400

Dave and Rosa are delivering meals to a daycare. Dave delivers 14 meals. Rosa delivers 5 meals. How many more meals does Dave deliver than Rosa? Use an equation and solve. 

5 + n = 14 

14-5= 9

n=9 more meals than Rosa

500

This year 45 students ran the track-a-thon. That is 9 times as many as last year. How many students ran the track-a-thon in the last two years?

1. Solve for last year 

9 x n = 45 

n=5 

2. Solve for last two years 

5+45= 50 students in all ran the track-a-thon for two years

Problem Solving

100

Sally had 6 seashells. Sara gave her 8 more. What is the equation AND what is the inverse operation?

6+8=14 AND 14-8=6 14-6=8

200

Mrs. Thomson gave the boys 17 stickers and gave the girls 23 stickers. How many stickers do the children have in all? Check it with the inverse operation.

17+23= 40 AND 40-23=17 40-17=23

300

The giraffe at the zoo stood 8 metres tall. The elephant was only 4 metres tall. How much taller is the giraffe than the elephant? Write the equation, solve it and check it with the inverse operation.

8- 4 = 4 4 = 4 =8

400

I had a bag with 278 beads. The bag had a hole and I dropped 137 beads. How many beads are left in the bag? Check your answer using the inverse operation.

278-137=141 141+137=278

500

There are 84 tiles in the kitchen and 37 in the bathroom. How many tiles are there altogether? Which problem could you use to check your answer? a. ____ - 37=84 b. ____ - 84=37 c. ____+ 84=37 d. 37+84= _____

a. ____-37=84