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 July 11 2026
05:01:07 AM | Saturday July 11 2026
05:01:07 AMFlip Answers |
| 1) | 390 * 410 = | | 1) 400 * 400 - 10 * 10 = 159900 |
| 2) | 108 * 92 = | | 2) 100 * 100 - 8 * 8 = 9936 |
| 3) | 309 * 291 = | | 3) 300 * 300 - 9 * 9 = 89919 |
| 4) | 292 * 308 = | | 4) 300 * 300 - 8 * 8 = 89936 |
| 5) | 99 * 101 = | | 5) 100 * 100 - 1 * 1 = 9999 |
| 6) | 394 * 406 = | | 6) 400 * 400 - 6 * 6 = 159964 |
| 7) | 291 * 309 = | | 7) 300 * 300 - 9 * 9 = 89919 |
| 8) | 309 * 291 = | | 8) 300 * 300 - 9 * 9 = 89919 |
| 9) | 205 * 195 = | | 9) 200 * 200 - 5 * 5 = 39975 |
| 10) | 410 * 390 = | | 10) 400 * 400 - 10 * 10 = 159900 |
| 11) | 30 * 60 + 30 * 40 = | | 11) ( 40 + 60) * 30 = 3000 |
| 12) | 41 * 45 + 55 * 41 = | | 12) ( 45 + 55) * 41 = 4100 |
| 13) | 71 * 235 - 71 * 35 = | | 13) ( 235 - 35) * 71 = 14200 |
| 14) | 74 * 48 + 52 * 74 = | | 14) ( 52 + 48) * 74 = 7400 |
| 15) | 43 * 56 + 44 * 43 = | | 15) ( 56 + 44) * 43 = 4300 |
| 16) | 69 * 41 + 69 * 59 = | | 16) ( 41 + 59) * 69 = 6900 |
| 17) | 53 * 45 + 55 * 53 = | | 17) ( 45 + 55) * 53 = 5300 |
| 18) | 25 * 57 + 25 * 43 = | | 18) ( 43 + 57) * 25 = 2500 |
| 19) | 34 * 259 - 34 * 59 = | | 19) ( 259 - 59) * 34 = 6800 |
| 20) | 96 * 255 - 55 * 96 = | | 20) ( 255 - 55) * 96 = 19200 |
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Score: ______________ | |
