Subtraction and addition to 20
(1) Enter the number in the box
| 4 + 7 = | 16 - = 1 | 18 - 7 = |
| 9 - 2 = | 18 - = 12 | 11 + 7 = |
| 4 + 2 = | 19 - = 16 | 12 + 2 = |
| 6 + 4 = | 17 - = 11 | 17 - 6 = |
| 7 + 7 = | 15 - = 13 | 13 + = 18 |
| 6 + 6 = | 14 - = 14 | 18 - = 12 |
| 10 - 7 = | 17 - = 8 | 17 - = 6 |
| 10 - 3 = | 10 + = 16 | 8 + = 16 |
| 8 - 4 = | 10 + = 17 | 4 + = 15 |
| 11 - 6 = | 15 + = 18 | + 4 = 9 |
| 20 - 10 = | 19 + = 20 | - 2 = 15 |
| 6 - 4 = | 16 - = 12 | + 2 = 9 |
| 16 + 3 = | 18 - = 14 | + 7 = 18 |
| 18 + 2 = | - 2 = 15 | - 5 = 14 |
| 19 - 4 = | + 10 = 16 | 17 + = 19 |
| 15 - 2 = | - 7 = 9 | 18 - = 12 |
| 13 + 5 = | 16 - = 14 | 13 - = 2 |
| 14 - 6 = | 18 - 4 = | 16 - 7 = |
| 16 - 4 = | 12 + 4 = | 6 + 6 = |