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
|
|
Wednesday April 08 2026
06:11:06 PM | Wednesday April 08 2026
06:11:06 PMFlip Answers |
| 1) | 399 * 401 = | | 1) 400 * 400 - 1 * 1 = 159999 |
| 2) | 393 * 407 = | | 2) 400 * 400 - 7 * 7 = 159951 |
| 3) | 197 * 203 = | | 3) 200 * 200 - 3 * 3 = 39991 |
| 4) | 197 * 203 = | | 4) 200 * 200 - 3 * 3 = 39991 |
| 5) | 390 * 410 = | | 5) 400 * 400 - 10 * 10 = 159900 |
| 6) | 405 * 395 = | | 6) 400 * 400 - 5 * 5 = 159975 |
| 7) | 105 * 95 = | | 7) 100 * 100 - 5 * 5 = 9975 |
| 8) | 306 * 294 = | | 8) 300 * 300 - 6 * 6 = 89964 |
| 9) | 93 * 107 = | | 9) 100 * 100 - 7 * 7 = 9951 |
| 10) | 191 * 209 = | | 10) 200 * 200 - 9 * 9 = 39919 |
| 11) | 162 * 28 + 38 * 28 = | | 11) ( 162 + 38) * 28 = 5600 |
| 12) | 21 * 54 + 46 * 21 = | | 12) ( 54 + 46) * 21 = 2100 |
| 13) | 86 * 137 - 37 * 86 = | | 13) ( 137 - 37) * 86 = 8600 |
| 14) | 136 * 41 + 64 * 41 = | | 14) ( 136 + 64) * 41 = 8200 |
| 15) | 26 * 36 + 64 * 26 = | | 15) ( 64 + 36) * 26 = 2600 |
| 16) | 36 * 132 + 68 * 36 = | | 16) ( 132 + 68) * 36 = 7200 |
| 17) | 55 * 51 + 55 * 49 = | | 17) ( 51 + 49) * 55 = 5500 |
| 18) | 77 * 174 - 74 * 77 = | | 18) ( 174 - 74) * 77 = 7700 |
| 19) | 154 * 93 - 54 * 93 = | | 19) ( 154 - 54) * 93 = 9300 |
| 20) | 25 * 246 - 46 * 25 = | | 20) ( 246 - 46) * 25 = 5000 |
|
Score: ______________ | |
