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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Tuesday September 16 2025
04:01:21 PM | Tuesday September 16 2025
04:01:21 PMFlip Answers |
| 1) | 309 * 291 = | | 1) 300 * 300 - 9 * 9 = 89919 |
| 2) | 102 * 98 = | | 2) 100 * 100 - 2 * 2 = 9996 |
| 3) | 393 * 407 = | | 3) 400 * 400 - 7 * 7 = 159951 |
| 4) | 410 * 390 = | | 4) 400 * 400 - 10 * 10 = 159900 |
| 5) | 98 * 102 = | | 5) 100 * 100 - 2 * 2 = 9996 |
| 6) | 405 * 395 = | | 6) 400 * 400 - 5 * 5 = 159975 |
| 7) | 204 * 196 = | | 7) 200 * 200 - 4 * 4 = 39984 |
| 8) | 399 * 401 = | | 8) 400 * 400 - 1 * 1 = 159999 |
| 9) | 394 * 406 = | | 9) 400 * 400 - 6 * 6 = 159964 |
| 10) | 91 * 109 = | | 10) 100 * 100 - 9 * 9 = 9919 |
| 11) | 168 * 66 - 68 * 66 = | | 11) ( 168 - 68) * 66 = 6600 |
| 12) | 60 * 70 + 70 * 40 = | | 12) ( 60 + 40) * 70 = 7000 |
| 13) | 65 * 249 - 49 * 65 = | | 13) ( 249 - 49) * 65 = 13000 |
| 14) | 64 * 250 - 64 * 50 = | | 14) ( 250 - 50) * 64 = 12800 |
| 15) | 88 * 150 - 50 * 88 = | | 15) ( 150 - 50) * 88 = 8800 |
| 16) | 83 * 46 + 54 * 83 = | | 16) ( 46 + 54) * 83 = 8300 |
| 17) | 85 * 61 + 39 * 85 = | | 17) ( 39 + 61) * 85 = 8500 |
| 18) | 30 * 86 + 70 * 86 = | | 18) ( 30 + 70) * 86 = 8600 |
| 19) | 51 * 158 + 51 * 42 = | | 19) ( 158 + 42) * 51 = 10200 |
| 20) | 162 * 46 - 62 * 46 = | | 20) ( 162 - 62) * 46 = 4600 |
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Score: ______________ | |
