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 January 29 2026
06:26:39 AM | Thursday January 29 2026
06:26:39 AMFlip Answers |
| 1) | 393 * 407 = | | 1) 400 * 400 - 7 * 7 = 159951 |
| 2) | 395 * 405 = | | 2) 400 * 400 - 5 * 5 = 159975 |
| 3) | 103 * 97 = | | 3) 100 * 100 - 3 * 3 = 9991 |
| 4) | 410 * 390 = | | 4) 400 * 400 - 10 * 10 = 159900 |
| 5) | 396 * 404 = | | 5) 400 * 400 - 4 * 4 = 159984 |
| 6) | 393 * 407 = | | 6) 400 * 400 - 7 * 7 = 159951 |
| 7) | 290 * 310 = | | 7) 300 * 300 - 10 * 10 = 89900 |
| 8) | 403 * 397 = | | 8) 400 * 400 - 3 * 3 = 159991 |
| 9) | 390 * 410 = | | 9) 400 * 400 - 10 * 10 = 159900 |
| 10) | 93 * 107 = | | 10) 100 * 100 - 7 * 7 = 9951 |
| 11) | 69 * 28 + 31 * 28 = | | 11) ( 31 + 69) * 28 = 2800 |
| 12) | 241 * 28 - 41 * 28 = | | 12) ( 241 - 41) * 28 = 5600 |
| 13) | 271 * 50 - 50 * 71 = | | 13) ( 271 - 71) * 50 = 10000 |
| 14) | 47 * 27 + 27 * 53 = | | 14) ( 47 + 53) * 27 = 2700 |
| 15) | 249 * 23 - 49 * 23 = | | 15) ( 249 - 49) * 23 = 4600 |
| 16) | 68 * 256 - 68 * 56 = | | 16) ( 256 - 56) * 68 = 13600 |
| 17) | 161 * 49 + 39 * 49 = | | 17) ( 161 + 39) * 49 = 9800 |
| 18) | 54 * 43 + 43 * 46 = | | 18) ( 54 + 46) * 43 = 4300 |
| 19) | 57 * 54 + 54 * 143 = | | 19) ( 143 + 57) * 54 = 10800 |
| 20) | 31 * 147 - 47 * 31 = | | 20) ( 147 - 47) * 31 = 3100 |
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Score: ______________ | |
