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 October 30 2026
07:54:00 AM | Friday October 30 2026
07:54:00 AMFlip Answers |
| 1) | 397 * 403 = | | 1) 400 * 400 - 3 * 3 = 159991 |
| 2) | 405 * 395 = | | 2) 400 * 400 - 5 * 5 = 159975 |
| 3) | 305 * 295 = | | 3) 300 * 300 - 5 * 5 = 89975 |
| 4) | 204 * 196 = | | 4) 200 * 200 - 4 * 4 = 39984 |
| 5) | 295 * 305 = | | 5) 300 * 300 - 5 * 5 = 89975 |
| 6) | 108 * 92 = | | 6) 100 * 100 - 8 * 8 = 9936 |
| 7) | 210 * 190 = | | 7) 200 * 200 - 10 * 10 = 39900 |
| 8) | 404 * 396 = | | 8) 400 * 400 - 4 * 4 = 159984 |
| 9) | 406 * 394 = | | 9) 400 * 400 - 6 * 6 = 159964 |
| 10) | 94 * 106 = | | 10) 100 * 100 - 6 * 6 = 9964 |
| 11) | 140 * 50 - 50 * 40 = | | 11) ( 140 - 40) * 50 = 5000 |
| 12) | 51 * 250 - 50 * 51 = | | 12) ( 250 - 50) * 51 = 10200 |
| 13) | 171 * 79 - 71 * 79 = | | 13) ( 171 - 71) * 79 = 7900 |
| 14) | 249 * 83 - 49 * 83 = | | 14) ( 249 - 49) * 83 = 16600 |
| 15) | 53 * 64 + 53 * 136 = | | 15) ( 136 + 64) * 53 = 10600 |
| 16) | 25 * 71 + 75 * 71 = | | 16) ( 25 + 75) * 71 = 7100 |
| 17) | 136 * 61 + 61 * 64 = | | 17) ( 136 + 64) * 61 = 12200 |
| 18) | 68 * 166 - 68 * 66 = | | 18) ( 166 - 66) * 68 = 6800 |
| 19) | 63 * 152 - 63 * 52 = | | 19) ( 152 - 52) * 63 = 6300 |
| 20) | 251 * 72 - 72 * 51 = | | 20) ( 251 - 51) * 72 = 14400 |
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Score: ______________ | |
