Subtract 8: Subtraction Facts
| 9 − 8 = 1 (matching addition: 8 + 1 = 9) |
| 10 − 8 = 2 (matching addition: 8 + 2 = 10) |
| 11 − 8 = 3 (matching addition: 8 + 3 = 11) |
| 12 − 8 = 4 (matching addition: 8 + 4 = 12) |
| 13 − 8 = 5 (matching addition: 8 + 5 = 13) |
| 14 − 8 = 6 (matching addition: 8 + 6 = 14) |
| 15 − 8 = 7 (matching addition: 8 + 7 = 15) |
| 16 − 8 = 8 (matching addition: 8 + 8 = 16) |
| 17 − 8 = 9 (matching addition: 8 + 9 = 17) |
| 18 − 8 = 10 (matching addition: 8 + 10 = 18) |
| 19 − 8 = 11 (matching addition: 8 + 11 = 19) |
| 20 − 8 = 12 (matching addition: 8 + 12 = 20) |
Zoorithmetic https://zoorithmetic.com/
Subtract 8 is two short of subtract 10, which makes it a close cousin of the easiest subtraction family.
The pattern in the answers
Every answer is 2 more than the starting number minus 10: 14 - 8 is 4 + 2, which is 6.
Tip for the subtract 8 facts
Take away 10, then add 2 back. For 13 - 8, 13 - 10 = 3, and 2 back gives 5.
The 3 hardest facts
- 13 − 8 = 5 (matching addition: 8 + 5 = 13)
- 14 − 8 = 6 (matching addition: 8 + 6 = 14)
- 15 − 8 = 7 (matching addition: 8 + 7 = 15)
The 'take ten, give two back' move is fast but needs practice; start with starting numbers 13 to 15, where the ten is easy to see.
Check with addition
Every subtraction fact is an addition fact turned around. Add the answer back to 8 to get the number you started with.
- 1 + 8 = 9, so 9 − 8 = 1
- 2 + 8 = 10, so 10 − 8 = 2
- 3 + 8 = 11, so 11 − 8 = 3
- 4 + 8 = 12, so 12 − 8 = 4
- 5 + 8 = 13, so 13 − 8 = 5
- 6 + 8 = 14, so 14 − 8 = 6
- 7 + 8 = 15, so 15 − 8 = 7
- 8 + 8 = 16, so 16 − 8 = 8
- 9 + 8 = 17, so 17 − 8 = 9
- 10 + 8 = 18, so 18 − 8 = 10
- 11 + 8 = 19, so 19 − 8 = 11
- 12 + 8 = 20, so 20 − 8 = 12
Play the subtract 8 facts game
Untimed by default. A missed fact shows its answer and comes back later in the round.
Printable subtract 8 chart
One US Letter page, clear in black and white.
Quick quiz: subtract 8 facts
10 questions, no timer. At the end you see the score, the facts to practice and a sheet you can print.
Questions parents ask
Why take 10 and then give 2 back?
8 is 10 minus 2, so removing 10 takes away 2 too many. Adding the 2 back fixes it.
What is the matching addition for 15 - 8?
8 + 7 = 15. Showing both side by side helps children trust the answer.