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 September 03 2026
11:58:16 AM | Thursday September 03 2026
11:58:16 AMFlip Answers |
| 1) | 291 * 309 = | | 1) 300 * 300 - 9 * 9 = 89919 |
| 2) | 90 * 110 = | | 2) 100 * 100 - 10 * 10 = 9900 |
| 3) | 408 * 392 = | | 3) 400 * 400 - 8 * 8 = 159936 |
| 4) | 95 * 105 = | | 4) 100 * 100 - 5 * 5 = 9975 |
| 5) | 393 * 407 = | | 5) 400 * 400 - 7 * 7 = 159951 |
| 6) | 410 * 390 = | | 6) 400 * 400 - 10 * 10 = 159900 |
| 7) | 405 * 395 = | | 7) 400 * 400 - 5 * 5 = 159975 |
| 8) | 397 * 403 = | | 8) 400 * 400 - 3 * 3 = 159991 |
| 9) | 404 * 396 = | | 9) 400 * 400 - 4 * 4 = 159984 |
| 10) | 105 * 95 = | | 10) 100 * 100 - 5 * 5 = 9975 |
| 11) | 77 * 54 + 146 * 77 = | | 11) ( 146 + 54) * 77 = 15400 |
| 12) | 57 * 47 + 43 * 47 = | | 12) ( 57 + 43) * 47 = 4700 |
| 13) | 92 * 150 + 92 * 50 = | | 13) ( 150 + 50) * 92 = 18400 |
| 14) | 82 * 161 - 61 * 82 = | | 14) ( 161 - 61) * 82 = 8200 |
| 15) | 77 * 147 - 47 * 77 = | | 15) ( 147 - 47) * 77 = 7700 |
| 16) | 29 * 149 + 29 * 51 = | | 16) ( 149 + 51) * 29 = 5800 |
| 17) | 139 * 24 - 24 * 39 = | | 17) ( 139 - 39) * 24 = 2400 |
| 18) | 238 * 49 - 38 * 49 = | | 18) ( 238 - 38) * 49 = 9800 |
| 19) | 89 * 42 + 89 * 58 = | | 19) ( 42 + 58) * 89 = 8900 |
| 20) | 51 * 267 - 67 * 51 = | | 20) ( 267 - 67) * 51 = 10200 |
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Score: ______________ | |
