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 March 21 2026
12:57:16 PM | Saturday March 21 2026
12:57:16 PMFlip Answers |
| 1) | 90 * 110 = | | 1) 100 * 100 - 10 * 10 = 9900 |
| 2) | 92 * 108 = | | 2) 100 * 100 - 8 * 8 = 9936 |
| 3) | 196 * 204 = | | 3) 200 * 200 - 4 * 4 = 39984 |
| 4) | 391 * 409 = | | 4) 400 * 400 - 9 * 9 = 159919 |
| 5) | 408 * 392 = | | 5) 400 * 400 - 8 * 8 = 159936 |
| 6) | 293 * 307 = | | 6) 300 * 300 - 7 * 7 = 89951 |
| 7) | 410 * 390 = | | 7) 400 * 400 - 10 * 10 = 159900 |
| 8) | 91 * 109 = | | 8) 100 * 100 - 9 * 9 = 9919 |
| 9) | 293 * 307 = | | 9) 300 * 300 - 7 * 7 = 89951 |
| 10) | 193 * 207 = | | 10) 200 * 200 - 7 * 7 = 39951 |
| 11) | 64 * 35 + 36 * 35 = | | 11) ( 64 + 36) * 35 = 3500 |
| 12) | 30 * 161 - 30 * 61 = | | 12) ( 161 - 61) * 30 = 3000 |
| 13) | 48 * 162 - 62 * 48 = | | 13) ( 162 - 62) * 48 = 4800 |
| 14) | 271 * 51 - 51 * 71 = | | 14) ( 271 - 71) * 51 = 10200 |
| 15) | 236 * 71 - 71 * 36 = | | 15) ( 236 - 36) * 71 = 14200 |
| 16) | 245 * 23 - 23 * 45 = | | 16) ( 245 - 45) * 23 = 4600 |
| 17) | 31 * 172 - 72 * 31 = | | 17) ( 172 - 72) * 31 = 3100 |
| 18) | 22 * 139 + 61 * 22 = | | 18) ( 139 + 61) * 22 = 4400 |
| 19) | 49 * 93 + 93 * 51 = | | 19) ( 49 + 51) * 93 = 9300 |
| 20) | 59 * 239 - 59 * 39 = | | 20) ( 239 - 39) * 59 = 11800 |
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Score: ______________ | |
