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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Saturday August 08 2026
02:38:09 PM | Saturday August 08 2026
02:38:09 PMFlip Answers |
| 1) | 399 * 401 = | | 1) 400 * 400 - 1 * 1 = 159999 |
| 2) | 307 * 293 = | | 2) 300 * 300 - 7 * 7 = 89951 |
| 3) | 102 * 98 = | | 3) 100 * 100 - 2 * 2 = 9996 |
| 4) | 93 * 107 = | | 4) 100 * 100 - 7 * 7 = 9951 |
| 5) | 199 * 201 = | | 5) 200 * 200 - 1 * 1 = 39999 |
| 6) | 207 * 193 = | | 6) 200 * 200 - 7 * 7 = 39951 |
| 7) | 191 * 209 = | | 7) 200 * 200 - 9 * 9 = 39919 |
| 8) | 193 * 207 = | | 8) 200 * 200 - 7 * 7 = 39951 |
| 9) | 393 * 407 = | | 9) 400 * 400 - 7 * 7 = 159951 |
| 10) | 290 * 310 = | | 10) 300 * 300 - 10 * 10 = 89900 |
| 11) | 261 * 68 - 68 * 61 = | | 11) ( 261 - 61) * 68 = 13600 |
| 12) | 41 * 162 - 41 * 62 = | | 12) ( 162 - 62) * 41 = 4100 |
| 13) | 256 * 60 - 56 * 60 = | | 13) ( 256 - 56) * 60 = 12000 |
| 14) | 86 * 145 + 55 * 86 = | | 14) ( 145 + 55) * 86 = 17200 |
| 15) | 264 * 76 - 64 * 76 = | | 15) ( 264 - 64) * 76 = 15200 |
| 16) | 93 * 166 - 93 * 66 = | | 16) ( 166 - 66) * 93 = 9300 |
| 17) | 245 * 69 - 69 * 45 = | | 17) ( 245 - 45) * 69 = 13800 |
| 18) | 71 * 95 + 129 * 95 = | | 18) ( 129 + 71) * 95 = 19000 |
| 19) | 239 * 88 - 88 * 39 = | | 19) ( 239 - 39) * 88 = 17600 |
| 20) | 81 * 130 + 70 * 81 = | | 20) ( 130 + 70) * 81 = 16200 |
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Score: ______________ | |
