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
|
|
Tuesday April 14 2026
04:35:54 PM | Tuesday April 14 2026
04:35:54 PMFlip Answers |
| 1) | 205 * 195 = | | 1) 200 * 200 - 5 * 5 = 39975 |
| 2) | 93 * 107 = | | 2) 100 * 100 - 7 * 7 = 9951 |
| 3) | 396 * 404 = | | 3) 400 * 400 - 4 * 4 = 159984 |
| 4) | 294 * 306 = | | 4) 300 * 300 - 6 * 6 = 89964 |
| 5) | 309 * 291 = | | 5) 300 * 300 - 9 * 9 = 89919 |
| 6) | 90 * 110 = | | 6) 100 * 100 - 10 * 10 = 9900 |
| 7) | 395 * 405 = | | 7) 400 * 400 - 5 * 5 = 159975 |
| 8) | 205 * 195 = | | 8) 200 * 200 - 5 * 5 = 39975 |
| 9) | 190 * 210 = | | 9) 200 * 200 - 10 * 10 = 39900 |
| 10) | 395 * 405 = | | 10) 400 * 400 - 5 * 5 = 159975 |
| 11) | 41 * 49 + 159 * 49 = | | 11) ( 159 + 41) * 49 = 9800 |
| 12) | 263 * 52 - 63 * 52 = | | 12) ( 263 - 63) * 52 = 10400 |
| 13) | 74 * 129 + 71 * 74 = | | 13) ( 129 + 71) * 74 = 14800 |
| 14) | 69 * 69 + 31 * 69 = | | 14) ( 31 + 69) * 69 = 6900 |
| 15) | 136 * 27 - 27 * 36 = | | 15) ( 136 - 36) * 27 = 2700 |
| 16) | 57 * 39 + 143 * 39 = | | 16) ( 143 + 57) * 39 = 7800 |
| 17) | 69 * 57 + 31 * 57 = | | 17) ( 31 + 69) * 57 = 5700 |
| 18) | 95 * 145 + 55 * 95 = | | 18) ( 145 + 55) * 95 = 19000 |
| 19) | 46 * 56 + 144 * 46 = | | 19) ( 144 + 56) * 46 = 9200 |
| 20) | 131 * 23 + 69 * 23 = | | 20) ( 131 + 69) * 23 = 4600 |
|
Score: ______________ | |
