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 May 21 2026
12:19:08 AM | Thursday May 21 2026
12:19:08 AMFlip Answers |
| 1) | 101 * 99 = | | 1) 100 * 100 - 1 * 1 = 9999 |
| 2) | 95 * 105 = | | 2) 100 * 100 - 5 * 5 = 9975 |
| 3) | 390 * 410 = | | 3) 400 * 400 - 10 * 10 = 159900 |
| 4) | 90 * 110 = | | 4) 100 * 100 - 10 * 10 = 9900 |
| 5) | 193 * 207 = | | 5) 200 * 200 - 7 * 7 = 39951 |
| 6) | 109 * 91 = | | 6) 100 * 100 - 9 * 9 = 9919 |
| 7) | 398 * 402 = | | 7) 400 * 400 - 2 * 2 = 159996 |
| 8) | 199 * 201 = | | 8) 200 * 200 - 1 * 1 = 39999 |
| 9) | 396 * 404 = | | 9) 400 * 400 - 4 * 4 = 159984 |
| 10) | 392 * 408 = | | 10) 400 * 400 - 8 * 8 = 159936 |
| 11) | 241 * 27 - 27 * 41 = | | 11) ( 241 - 41) * 27 = 5400 |
| 12) | 37 * 151 - 37 * 51 = | | 12) ( 151 - 51) * 37 = 3700 |
| 13) | 28 * 61 + 139 * 28 = | | 13) ( 139 + 61) * 28 = 5600 |
| 14) | 136 * 91 - 36 * 91 = | | 14) ( 136 - 36) * 91 = 9100 |
| 15) | 56 * 249 - 56 * 49 = | | 15) ( 249 - 49) * 56 = 11200 |
| 16) | 149 * 21 - 49 * 21 = | | 16) ( 149 - 49) * 21 = 2100 |
| 17) | 256 * 96 - 96 * 56 = | | 17) ( 256 - 56) * 96 = 19200 |
| 18) | 49 * 92 + 92 * 151 = | | 18) ( 151 + 49) * 92 = 18400 |
| 19) | 271 * 90 - 90 * 71 = | | 19) ( 271 - 71) * 90 = 18000 |
| 20) | 77 * 57 + 77 * 143 = | | 20) ( 143 + 57) * 77 = 15400 |
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Score: ______________ | |
