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 October 28 2026
07:11:31 AM | Wednesday October 28 2026
07:11:31 AMFlip Answers |
| 1) | 410 * 390 = | | 1) 400 * 400 - 10 * 10 = 159900 |
| 2) | 303 * 297 = | | 2) 300 * 300 - 3 * 3 = 89991 |
| 3) | 201 * 199 = | | 3) 200 * 200 - 1 * 1 = 39999 |
| 4) | 205 * 195 = | | 4) 200 * 200 - 5 * 5 = 39975 |
| 5) | 406 * 394 = | | 5) 400 * 400 - 6 * 6 = 159964 |
| 6) | 96 * 104 = | | 6) 100 * 100 - 4 * 4 = 9984 |
| 7) | 191 * 209 = | | 7) 200 * 200 - 9 * 9 = 39919 |
| 8) | 404 * 396 = | | 8) 400 * 400 - 4 * 4 = 159984 |
| 9) | 406 * 394 = | | 9) 400 * 400 - 6 * 6 = 159964 |
| 10) | 104 * 96 = | | 10) 100 * 100 - 4 * 4 = 9984 |
| 11) | 69 * 170 - 70 * 69 = | | 11) ( 170 - 70) * 69 = 6900 |
| 12) | 49 * 95 + 95 * 51 = | | 12) ( 49 + 51) * 95 = 9500 |
| 13) | 65 * 68 + 68 * 35 = | | 13) ( 65 + 35) * 68 = 6800 |
| 14) | 165 * 96 + 96 * 35 = | | 14) ( 165 + 35) * 96 = 19200 |
| 15) | 64 * 136 + 64 * 64 = | | 15) ( 136 + 64) * 64 = 12800 |
| 16) | 85 * 256 - 85 * 56 = | | 16) ( 256 - 56) * 85 = 17000 |
| 17) | 56 * 236 - 56 * 36 = | | 17) ( 236 - 36) * 56 = 11200 |
| 18) | 150 * 58 + 58 * 50 = | | 18) ( 150 + 50) * 58 = 11600 |
| 19) | 86 * 141 + 59 * 86 = | | 19) ( 141 + 59) * 86 = 17200 |
| 20) | 54 * 147 - 54 * 47 = | | 20) ( 147 - 47) * 54 = 5400 |
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Score: ______________ | |
