| 1) | 251 − 109 = | 2) | -841 + 221 = | 3) | 24 − 144 = |
| 4) | 938 + 734 = | 5) | -890 − 880 = | 6) | 387 + 406 = |
| 1) | 251 − 109 = 142 | 2) | -841 + 221 = -620 | 3) | 24 − 144 = -120 |
| 4) | 938 + 734 = 1672 | 5) | -890 − 880 = -1770 | 6) | 387 + 406 = 793 |