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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Thursday April 23 2026
08:36:19 PM | Thursday April 23 2026
08:36:19 PMFlip Answers |
| 1) | 205 * 195 = | | 1) 200 * 200 - 5 * 5 = 39975 |
| 2) | 392 * 408 = | | 2) 400 * 400 - 8 * 8 = 159936 |
| 3) | 204 * 196 = | | 3) 200 * 200 - 4 * 4 = 39984 |
| 4) | 408 * 392 = | | 4) 400 * 400 - 8 * 8 = 159936 |
| 5) | 401 * 399 = | | 5) 400 * 400 - 1 * 1 = 159999 |
| 6) | 197 * 203 = | | 6) 200 * 200 - 3 * 3 = 39991 |
| 7) | 410 * 390 = | | 7) 400 * 400 - 10 * 10 = 159900 |
| 8) | 305 * 295 = | | 8) 300 * 300 - 5 * 5 = 89975 |
| 9) | 109 * 91 = | | 9) 100 * 100 - 9 * 9 = 9919 |
| 10) | 299 * 301 = | | 10) 300 * 300 - 1 * 1 = 89999 |
| 11) | 140 * 69 - 40 * 69 = | | 11) ( 140 - 40) * 69 = 6900 |
| 12) | 57 * 59 + 59 * 43 = | | 12) ( 57 + 43) * 59 = 5900 |
| 13) | 36 * 147 + 36 * 53 = | | 13) ( 147 + 53) * 36 = 7200 |
| 14) | 63 * 158 - 63 * 58 = | | 14) ( 158 - 58) * 63 = 6300 |
| 15) | 75 * 51 + 51 * 125 = | | 15) ( 125 + 75) * 51 = 10200 |
| 16) | 47 * 31 + 31 * 53 = | | 16) ( 53 + 47) * 31 = 3100 |
| 17) | 84 * 236 - 36 * 84 = | | 17) ( 236 - 36) * 84 = 16800 |
| 18) | 63 * 94 + 94 * 137 = | | 18) ( 137 + 63) * 94 = 18800 |
| 19) | 90 * 37 + 90 * 63 = | | 19) ( 63 + 37) * 90 = 9000 |
| 20) | 46 * 55 + 145 * 46 = | | 20) ( 145 + 55) * 46 = 9200 |
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Score: ______________ | |
