| 1) | 951 − 20 = | 2) | 544 + 449 = | 3) | 763 − 770 = |
| 4) | 807 + 552 = | 5) | -146 + 561 = | 6) | -451 + 848 = |
| 1) | 951 − 20 = 931 | 2) | 544 + 449 = 993 | 3) | 763 − 770 = -7 |
| 4) | 807 + 552 = 1359 | 5) | -146 + 561 = 415 | 6) | -451 + 848 = 397 |