Start at the larger number and count backwards.

15 − 4 = ?

15... 14, 13, 12, 11

Answer: 11

Turn the subtraction into an addition question.

13 − 6 = ?

Think: 6 + ? = 13

6 + 7 = 13, so answer: 7

Jump backwards on a number line.

17 − 5 = ?

12 → 13 → 14 → 15 → 16 → 17

Jump back 5: answer = 12

Addition and subtraction facts are related!

Fact family for 8, 5, 13:

8 + 5 = 13 | 5 + 8 = 13

13 − 5 = 8 | 13 − 8 = 5

Subtraction as “Missing Part”

A number bond shows the whole and its two parts. If you know the whole and one part, subtract to find the missing part.

18 − 9 = 9

20 − 12 = 8

Key Vocabulary

subtract — to take away one number from another

difference — the answer when you subtract

count back — start at the larger number and jump backwards

fact family — a group of addition and subtraction facts using the same three numbers

✓Subtraction means taking away. The answer is called the difference.
✓Count back by jumping backwards from the larger number.
✓Think addition: turn 14 − 6 into 6 + ? = 14 to find the answer.
✓Fact families show how addition and subtraction are related using the same three numbers.