Subtraction Table for 20
Each row subtracts numbers 1 through 12 from 20. Subtraction is the inverse of addition and appears in change-making, scores, and measurements.
Every difference here stays whole and non-negative — the smallest is 20 − 12 = 8. Subtract an even number and parity survives; subtract an odd and it flips: 20 − 3 = 17. Taking away 10 moves only the tens digit: 20 − 10 = 10, and nothing else in the number moves. Read the difference column bottom-up and it climbs, one step at a time, back to 19 — a countdown fully reversed.
| Subtrahend | Difference |
|---|---|
| 20 − 1 | 19 |
| 20 − 2 | 18 |
| 20 − 3 | 17 |
| 20 − 4 | 16 |
| 20 − 5 | 15 |
| 20 − 6 | 14 |
| 20 − 7 | 13 |
| 20 − 8 | 12 |
| 20 − 9 | 11 |
| 20 − 10 | 10 |
| 20 − 11 | 9 |
| 20 − 12 | 8 |
Frequently asked questions
What is 20 − 4?
20 − 4 = 16.
What does the difference column mean?
The difference is the result after subtracting — here, the second number in each row, such as 20 − 2 = 18.
Is subtraction commutative?
No — swapping the order changes the result: 20 − 3 = 17, but 3 − 20 = -17. That is why reading the row direction matters.