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 October 03 2026
10:01:01 AM | Saturday October 03 2026
10:01:01 AMFlip Answers |
| 1) | 393 * 407 = | | 1) 400 * 400 - 7 * 7 = 159951 |
| 2) | 393 * 407 = | | 2) 400 * 400 - 7 * 7 = 159951 |
| 3) | 395 * 405 = | | 3) 400 * 400 - 5 * 5 = 159975 |
| 4) | 190 * 210 = | | 4) 200 * 200 - 10 * 10 = 39900 |
| 5) | 398 * 402 = | | 5) 400 * 400 - 2 * 2 = 159996 |
| 6) | 399 * 401 = | | 6) 400 * 400 - 1 * 1 = 159999 |
| 7) | 310 * 290 = | | 7) 300 * 300 - 10 * 10 = 89900 |
| 8) | 106 * 94 = | | 8) 100 * 100 - 6 * 6 = 9964 |
| 9) | 99 * 101 = | | 9) 100 * 100 - 1 * 1 = 9999 |
| 10) | 390 * 410 = | | 10) 400 * 400 - 10 * 10 = 159900 |
| 11) | 235 * 29 - 35 * 29 = | | 11) ( 235 - 35) * 29 = 5800 |
| 12) | 97 * 42 + 58 * 97 = | | 12) ( 42 + 58) * 97 = 9700 |
| 13) | 75 * 237 - 75 * 37 = | | 13) ( 237 - 37) * 75 = 15000 |
| 14) | 47 * 57 + 43 * 47 = | | 14) ( 57 + 43) * 47 = 4700 |
| 15) | 75 * 154 + 46 * 75 = | | 15) ( 154 + 46) * 75 = 15000 |
| 16) | 261 * 61 - 61 * 61 = | | 16) ( 261 - 61) * 61 = 12200 |
| 17) | 35 * 55 + 65 * 55 = | | 17) ( 35 + 65) * 55 = 5500 |
| 18) | 271 * 56 - 71 * 56 = | | 18) ( 271 - 71) * 56 = 11200 |
| 19) | 159 * 29 + 41 * 29 = | | 19) ( 159 + 41) * 29 = 5800 |
| 20) | 65 * 64 + 65 * 136 = | | 20) ( 136 + 64) * 65 = 13000 |
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Score: ______________ | |
