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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Saturday May 09 2026
08:24:19 AM | Saturday May 09 2026
08:24:19 AMFlip Answers |
| 1) | 205 * 195 = | | 1) 200 * 200 - 5 * 5 = 39975 |
| 2) | 209 * 191 = | | 2) 200 * 200 - 9 * 9 = 39919 |
| 3) | 191 * 209 = | | 3) 200 * 200 - 9 * 9 = 39919 |
| 4) | 303 * 297 = | | 4) 300 * 300 - 3 * 3 = 89991 |
| 5) | 410 * 390 = | | 5) 400 * 400 - 10 * 10 = 159900 |
| 6) | 392 * 408 = | | 6) 400 * 400 - 8 * 8 = 159936 |
| 7) | 202 * 198 = | | 7) 200 * 200 - 2 * 2 = 39996 |
| 8) | 396 * 404 = | | 8) 400 * 400 - 4 * 4 = 159984 |
| 9) | 95 * 105 = | | 9) 100 * 100 - 5 * 5 = 9975 |
| 10) | 207 * 193 = | | 10) 200 * 200 - 7 * 7 = 39951 |
| 11) | 30 * 249 - 30 * 49 = | | 11) ( 249 - 49) * 30 = 6000 |
| 12) | 35 * 35 + 65 * 35 = | | 12) ( 65 + 35) * 35 = 3500 |
| 13) | 21 * 169 - 69 * 21 = | | 13) ( 169 - 69) * 21 = 2100 |
| 14) | 45 * 58 + 155 * 58 = | | 14) ( 155 + 45) * 58 = 11600 |
| 15) | 136 * 46 - 46 * 36 = | | 15) ( 136 - 36) * 46 = 4600 |
| 16) | 237 * 81 - 81 * 37 = | | 16) ( 237 - 37) * 81 = 16200 |
| 17) | 140 * 49 - 49 * 40 = | | 17) ( 140 - 40) * 49 = 4900 |
| 18) | 83 * 267 - 67 * 83 = | | 18) ( 267 - 67) * 83 = 16600 |
| 19) | 53 * 25 + 47 * 25 = | | 19) ( 47 + 53) * 25 = 2500 |
| 20) | 38 * 40 + 60 * 38 = | | 20) ( 40 + 60) * 38 = 3800 |
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Score: ______________ | |
