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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Wednesday July 01 2026
09:16:28 PM | Wednesday July 01 2026
09:16:28 PMFlip Answers |
| 1) | 290 * 310 = | | 1) 300 * 300 - 10 * 10 = 89900 |
| 2) | 394 * 406 = | | 2) 400 * 400 - 6 * 6 = 159964 |
| 3) | 410 * 390 = | | 3) 400 * 400 - 10 * 10 = 159900 |
| 4) | 91 * 109 = | | 4) 100 * 100 - 9 * 9 = 9919 |
| 5) | 110 * 90 = | | 5) 100 * 100 - 10 * 10 = 9900 |
| 6) | 405 * 395 = | | 6) 400 * 400 - 5 * 5 = 159975 |
| 7) | 193 * 207 = | | 7) 200 * 200 - 7 * 7 = 39951 |
| 8) | 192 * 208 = | | 8) 200 * 200 - 8 * 8 = 39936 |
| 9) | 407 * 393 = | | 9) 400 * 400 - 7 * 7 = 159951 |
| 10) | 293 * 307 = | | 10) 300 * 300 - 7 * 7 = 89951 |
| 11) | 56 * 30 + 44 * 30 = | | 11) ( 56 + 44) * 30 = 3000 |
| 12) | 272 * 76 - 72 * 76 = | | 12) ( 272 - 72) * 76 = 15200 |
| 13) | 63 * 87 + 137 * 87 = | | 13) ( 137 + 63) * 87 = 17400 |
| 14) | 71 * 50 + 71 * 150 = | | 14) ( 150 + 50) * 71 = 14200 |
| 15) | 257 * 55 - 57 * 55 = | | 15) ( 257 - 57) * 55 = 11000 |
| 16) | 95 * 172 - 72 * 95 = | | 16) ( 172 - 72) * 95 = 9500 |
| 17) | 141 * 94 - 94 * 41 = | | 17) ( 141 - 41) * 94 = 9400 |
| 18) | 31 * 50 + 31 * 50 = | | 18) ( 50 + 50) * 31 = 3100 |
| 19) | 36 * 93 + 93 * 164 = | | 19) ( 164 + 36) * 93 = 18600 |
| 20) | 92 * 50 + 150 * 92 = | | 20) ( 150 + 50) * 92 = 18400 |
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Score: ______________ | |
