Math Main Page => Exercises - Math III
|
Goal: to practice how to make use of distributive property on special numbers, like (A + B) * (A - B) = A*A - B*B, A*C +B*C = (A + B ) *C, A*C - B*C = (A-B) * C
|
|
Sunday April 19 2026
01:03:34 PM | Sunday April 19 2026
01:03:34 PMFlip Answers |
| 1) | 110 * 90 = | | 1) 100 * 100 - 10 * 10 = 9900 |
| 2) | 303 * 297 = | | 2) 300 * 300 - 3 * 3 = 89991 |
| 3) | 308 * 292 = | | 3) 300 * 300 - 8 * 8 = 89936 |
| 4) | 393 * 407 = | | 4) 400 * 400 - 7 * 7 = 159951 |
| 5) | 391 * 409 = | | 5) 400 * 400 - 9 * 9 = 159919 |
| 6) | 93 * 107 = | | 6) 100 * 100 - 7 * 7 = 9951 |
| 7) | 104 * 96 = | | 7) 100 * 100 - 4 * 4 = 9984 |
| 8) | 292 * 308 = | | 8) 300 * 300 - 8 * 8 = 89936 |
| 9) | 391 * 409 = | | 9) 400 * 400 - 9 * 9 = 159919 |
| 10) | 309 * 291 = | | 10) 300 * 300 - 9 * 9 = 89919 |
| 11) | 45 * 70 + 70 * 155 = | | 11) ( 155 + 45) * 70 = 14000 |
| 12) | 163 * 85 - 85 * 63 = | | 12) ( 163 - 63) * 85 = 8500 |
| 13) | 56 * 126 + 56 * 74 = | | 13) ( 126 + 74) * 56 = 11200 |
| 14) | 239 * 97 - 97 * 39 = | | 14) ( 239 - 39) * 97 = 19400 |
| 15) | 260 * 66 - 60 * 66 = | | 15) ( 260 - 60) * 66 = 13200 |
| 16) | 246 * 49 - 49 * 46 = | | 16) ( 246 - 46) * 49 = 9800 |
| 17) | 38 * 68 + 68 * 62 = | | 17) ( 62 + 38) * 68 = 6800 |
| 18) | 242 * 50 - 42 * 50 = | | 18) ( 242 - 42) * 50 = 10000 |
| 19) | 58 * 60 + 40 * 58 = | | 19) ( 40 + 60) * 58 = 5800 |
| 20) | 265 * 69 - 65 * 69 = | | 20) ( 265 - 65) * 69 = 13800 |
|
Score: ______________ | |
