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 September 05 2026
01:29:00 PM | Saturday September 05 2026
01:29:00 PMFlip Answers |
| 1) | 410 * 390 = | | 1) 400 * 400 - 10 * 10 = 159900 |
| 2) | 292 * 308 = | | 2) 300 * 300 - 8 * 8 = 89936 |
| 3) | 392 * 408 = | | 3) 400 * 400 - 8 * 8 = 159936 |
| 4) | 390 * 410 = | | 4) 400 * 400 - 10 * 10 = 159900 |
| 5) | 410 * 390 = | | 5) 400 * 400 - 10 * 10 = 159900 |
| 6) | 196 * 204 = | | 6) 200 * 200 - 4 * 4 = 39984 |
| 7) | 299 * 301 = | | 7) 300 * 300 - 1 * 1 = 89999 |
| 8) | 209 * 191 = | | 8) 200 * 200 - 9 * 9 = 39919 |
| 9) | 309 * 291 = | | 9) 300 * 300 - 9 * 9 = 89919 |
| 10) | 407 * 393 = | | 10) 400 * 400 - 7 * 7 = 159951 |
| 11) | 141 * 46 + 59 * 46 = | | 11) ( 141 + 59) * 46 = 9200 |
| 12) | 158 * 43 - 43 * 58 = | | 12) ( 158 - 58) * 43 = 4300 |
| 13) | 24 * 135 - 35 * 24 = | | 13) ( 135 - 35) * 24 = 2400 |
| 14) | 21 * 236 - 21 * 36 = | | 14) ( 236 - 36) * 21 = 4200 |
| 15) | 138 * 87 - 38 * 87 = | | 15) ( 138 - 38) * 87 = 8700 |
| 16) | 165 * 34 + 34 * 35 = | | 16) ( 165 + 35) * 34 = 6800 |
| 17) | 144 * 64 - 64 * 44 = | | 17) ( 144 - 44) * 64 = 6400 |
| 18) | 44 * 40 + 160 * 44 = | | 18) ( 160 + 40) * 44 = 8800 |
| 19) | 27 * 52 + 73 * 52 = | | 19) ( 27 + 73) * 52 = 5200 |
| 20) | 168 * 67 - 67 * 68 = | | 20) ( 168 - 68) * 67 = 6700 |
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Score: ______________ | |
