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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Wednesday March 04 2026
08:32:58 PM | Wednesday March 04 2026
08:32:58 PMFlip Answers |
| 1) | 210 * 190 = | | 1) 200 * 200 - 10 * 10 = 39900 |
| 2) | 393 * 407 = | | 2) 400 * 400 - 7 * 7 = 159951 |
| 3) | 393 * 407 = | | 3) 400 * 400 - 7 * 7 = 159951 |
| 4) | 103 * 97 = | | 4) 100 * 100 - 3 * 3 = 9991 |
| 5) | 305 * 295 = | | 5) 300 * 300 - 5 * 5 = 89975 |
| 6) | 104 * 96 = | | 6) 100 * 100 - 4 * 4 = 9984 |
| 7) | 390 * 410 = | | 7) 400 * 400 - 10 * 10 = 159900 |
| 8) | 296 * 304 = | | 8) 300 * 300 - 4 * 4 = 89984 |
| 9) | 390 * 410 = | | 9) 400 * 400 - 10 * 10 = 159900 |
| 10) | 291 * 309 = | | 10) 300 * 300 - 9 * 9 = 89919 |
| 11) | 65 * 42 + 65 * 158 = | | 11) ( 158 + 42) * 65 = 13000 |
| 12) | 147 * 22 + 53 * 22 = | | 12) ( 147 + 53) * 22 = 4400 |
| 13) | 146 * 79 - 46 * 79 = | | 13) ( 146 - 46) * 79 = 7900 |
| 14) | 270 * 31 - 31 * 70 = | | 14) ( 270 - 70) * 31 = 6200 |
| 15) | 272 * 93 - 72 * 93 = | | 15) ( 272 - 72) * 93 = 18600 |
| 16) | 63 * 27 + 37 * 27 = | | 16) ( 37 + 63) * 27 = 2700 |
| 17) | 272 * 43 - 43 * 72 = | | 17) ( 272 - 72) * 43 = 8600 |
| 18) | 85 * 162 - 62 * 85 = | | 18) ( 162 - 62) * 85 = 8500 |
| 19) | 57 * 74 + 43 * 74 = | | 19) ( 57 + 43) * 74 = 7400 |
| 20) | 43 * 144 - 43 * 44 = | | 20) ( 144 - 44) * 43 = 4300 |
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Score: ______________ | |
