| 1) | 15 − 5 = | 2) | 644 − 550 = | 3) | -136 − 426 = |
| 4) | -461 + 299 = | 5) | 699 + 680 = | 6) | 81 + 516 = |
| 1) | 15 − 5 = 10 | 2) | 644 − 550 = 94 | 3) | -136 − 426 = -562 |
| 4) | -461 + 299 = -162 | 5) | 699 + 680 = 1379 | 6) | 81 + 516 = 597 |