Calculating

Connecting + and −

Name: ______________________________Date: ______________Score: ______ / 20

1.
4 + 6 = 10. What is the inverse (opposite) calculation?
1. A10 - 6 = 4
2. B10 + 6 = 16
3. C6 - 4 = 2
2.
12 + 7 = 19. Use the inverse: 19 - 7 = ?
3.
17 - 6 = 11. Use the inverse: 11 + 6 = ?
4.
Which is the inverse of 21 + 26 = 47?
1. A47 - 26 = 21
2. B47 + 21 = 68
3. C26 - 21 = 5
5.
Addition and subtraction are inverse (opposite) operations.
True False
6.
39 - 16 = 23. Use the inverse to check: 23 + 16 = ?
7.
The inverse of 10 - 8 = 2 is 2 + 8 = 10.
True False
8.
The numbers 3, 5 and 8 make a fact family. Which fact belongs to it?
1. A5 + 3 = 8
2. B5 + 4 = 9
3. C8 + 3 = 11
9.
Fact family for 3, 5 and 8: 8 - 3 = ?
10.
Fact family for 3, 5 and 8: 8 - 5 = ?
11.
The numbers 3, 6 and 9 make a fact family. Which subtraction belongs to it?
1. A9 - 6 = 3
2. B9 - 4 = 5
3. C6 - 3 = 3
12.
Fact family for 3, 6 and 9: 6 + 3 = ?
13.
How many calculations are in a fact family for 3 numbers like 3, 6 and 9?
1. A2
2. B4
3. C6
14.
Fact family for 8, 9 and 17: 17 - 9 = ?
15.
Fact family for 8, 9 and 17: 8 + 9 = ?
16.
Which fact does NOT belong to the fact family 24, 35 and 59?
1. A24 + 35 = 59
2. B59 - 24 = 35
3. C59 - 30 = 29
17.
Fact family for 24, 35 and 59: 59 - 35 = ?
18.
A number bond for 10: 6 + ? = 10.
19.
A number bond for 10: 7 + ? = 10.
20.
Which pair is a number bond for 10?
1. A8 + 2
2. B8 + 3
3. C7 + 2

Answer key

Calculating — Connecting + and −