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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Friday May 15 2026
11:10:35 PM | Friday May 15 2026
11:10:35 PMFlip Answers |
| 1) | 105 * 95 = | | 1) 100 * 100 - 5 * 5 = 9975 |
| 2) | 295 * 305 = | | 2) 300 * 300 - 5 * 5 = 89975 |
| 3) | 398 * 402 = | | 3) 400 * 400 - 2 * 2 = 159996 |
| 4) | 298 * 302 = | | 4) 300 * 300 - 2 * 2 = 89996 |
| 5) | 308 * 292 = | | 5) 300 * 300 - 8 * 8 = 89936 |
| 6) | 391 * 409 = | | 6) 400 * 400 - 9 * 9 = 159919 |
| 7) | 309 * 291 = | | 7) 300 * 300 - 9 * 9 = 89919 |
| 8) | 293 * 307 = | | 8) 300 * 300 - 7 * 7 = 89951 |
| 9) | 208 * 192 = | | 9) 200 * 200 - 8 * 8 = 39936 |
| 10) | 401 * 399 = | | 10) 400 * 400 - 1 * 1 = 159999 |
| 11) | 35 * 72 + 65 * 72 = | | 11) ( 35 + 65) * 72 = 7200 |
| 12) | 73 * 39 + 73 * 61 = | | 12) ( 39 + 61) * 73 = 7300 |
| 13) | 39 * 29 + 29 * 61 = | | 13) ( 61 + 39) * 29 = 2900 |
| 14) | 31 * 133 + 31 * 67 = | | 14) ( 133 + 67) * 31 = 6200 |
| 15) | 88 * 31 + 69 * 88 = | | 15) ( 31 + 69) * 88 = 8800 |
| 16) | 172 * 54 - 72 * 54 = | | 16) ( 172 - 72) * 54 = 5400 |
| 17) | 52 * 36 + 36 * 48 = | | 17) ( 48 + 52) * 36 = 3600 |
| 18) | 159 * 66 + 41 * 66 = | | 18) ( 159 + 41) * 66 = 13200 |
| 19) | 45 * 58 + 45 * 142 = | | 19) ( 142 + 58) * 45 = 9000 |
| 20) | 62 * 146 + 62 * 54 = | | 20) ( 146 + 54) * 62 = 12400 |
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Score: ______________ | |
