Vocabulary
Inverse of Addition
Inverse of Subtraction
Inverse Operations
Problem Solving
100
When you find out how many in all, combined, total or how much altogether what is the operation called?
addition
100
13 - 8 = 5
What is the inverse of 8 + 5 = 13
100
11-6=5
5+6=11 or 6+5=11
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. 

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
When you find out how many are left, or the difference, what is that operation called?
Subtraction
200
9+8=17 What is the inverse?
17-8=9 or 17-9=8
200
9-7=2
7+2=9 or 2+7=9
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 

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
What is the inverse of addition?
Subtraction
300
45+13=? What is the inverse?
58-13=45 or 58-45=13
300
83-41=? What is the inverse?
42+41=83 or 41+42=83
300

sixteen + nine = ____________ What is the inverse operation?

25-9=16 or 25-16=9

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
What is the inverse of multiplication?
Division
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
400
Which problem is the inverse of 24-15=___ ? a. 24-5=19 b. 9+5= 14 c. 15+9=24 d. 159
c
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

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
What is another word for the "opposite" operation?
inverse
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
500
35 + 135 = 170
What is the inverse of 170 - 135?
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

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
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