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
02:16:02 AM | Friday May 15 2026
02:16:02 AMFlip Answers |
| 1) | 391 * 409 = | | 1) 400 * 400 - 9 * 9 = 159919 |
| 2) | 102 * 98 = | | 2) 100 * 100 - 2 * 2 = 9996 |
| 3) | 396 * 404 = | | 3) 400 * 400 - 4 * 4 = 159984 |
| 4) | 407 * 393 = | | 4) 400 * 400 - 7 * 7 = 159951 |
| 5) | 408 * 392 = | | 5) 400 * 400 - 8 * 8 = 159936 |
| 6) | 108 * 92 = | | 6) 100 * 100 - 8 * 8 = 9936 |
| 7) | 290 * 310 = | | 7) 300 * 300 - 10 * 10 = 89900 |
| 8) | 302 * 298 = | | 8) 300 * 300 - 2 * 2 = 89996 |
| 9) | 209 * 191 = | | 9) 200 * 200 - 9 * 9 = 39919 |
| 10) | 294 * 306 = | | 10) 300 * 300 - 6 * 6 = 89964 |
| 11) | 44 * 51 + 44 * 49 = | | 11) ( 51 + 49) * 44 = 4400 |
| 12) | 136 * 60 + 64 * 60 = | | 12) ( 136 + 64) * 60 = 12000 |
| 13) | 143 * 64 - 43 * 64 = | | 13) ( 143 - 43) * 64 = 6400 |
| 14) | 75 * 144 + 56 * 75 = | | 14) ( 144 + 56) * 75 = 15000 |
| 15) | 143 * 68 - 43 * 68 = | | 15) ( 143 - 43) * 68 = 6800 |
| 16) | 274 * 60 - 60 * 74 = | | 16) ( 274 - 74) * 60 = 12000 |
| 17) | 165 * 73 + 73 * 35 = | | 17) ( 165 + 35) * 73 = 14600 |
| 18) | 161 * 52 + 52 * 39 = | | 18) ( 161 + 39) * 52 = 10400 |
| 19) | 41 * 32 + 41 * 68 = | | 19) ( 32 + 68) * 41 = 4100 |
| 20) | 147 * 26 + 53 * 26 = | | 20) ( 147 + 53) * 26 = 5200 |
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Score: ______________ | |
