Math Main Page => Exercises - Math III
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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
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Thursday July 23 2026
06:47:56 PM | Thursday July 23 2026
06:47:56 PMFlip Answers |
| 1) | 91 * 109 = | | 1) 100 * 100 - 9 * 9 = 9919 |
| 2) | 202 * 198 = | | 2) 200 * 200 - 2 * 2 = 39996 |
| 3) | 94 * 106 = | | 3) 100 * 100 - 6 * 6 = 9964 |
| 4) | 397 * 403 = | | 4) 400 * 400 - 3 * 3 = 159991 |
| 5) | 190 * 210 = | | 5) 200 * 200 - 10 * 10 = 39900 |
| 6) | 305 * 295 = | | 6) 300 * 300 - 5 * 5 = 89975 |
| 7) | 392 * 408 = | | 7) 400 * 400 - 8 * 8 = 159936 |
| 8) | 406 * 394 = | | 8) 400 * 400 - 6 * 6 = 159964 |
| 9) | 392 * 408 = | | 9) 400 * 400 - 8 * 8 = 159936 |
| 10) | 401 * 399 = | | 10) 400 * 400 - 1 * 1 = 159999 |
| 11) | 249 * 45 - 45 * 49 = | | 11) ( 249 - 49) * 45 = 9000 |
| 12) | 139 * 31 - 31 * 39 = | | 12) ( 139 - 39) * 31 = 3100 |
| 13) | 156 * 39 + 44 * 39 = | | 13) ( 156 + 44) * 39 = 7800 |
| 14) | 143 * 84 - 84 * 43 = | | 14) ( 143 - 43) * 84 = 8400 |
| 15) | 49 * 256 - 49 * 56 = | | 15) ( 256 - 56) * 49 = 9800 |
| 16) | 35 * 72 + 35 * 128 = | | 16) ( 128 + 72) * 35 = 7000 |
| 17) | 54 * 152 + 48 * 54 = | | 17) ( 152 + 48) * 54 = 10800 |
| 18) | 67 * 81 + 33 * 81 = | | 18) ( 33 + 67) * 81 = 8100 |
| 19) | 145 * 56 - 56 * 45 = | | 19) ( 145 - 45) * 56 = 5600 |
| 20) | 26 * 142 - 26 * 42 = | | 20) ( 142 - 42) * 26 = 2600 |
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Score: ______________ | |
