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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Wednesday February 25 2026
04:13:31 PM | Wednesday February 25 2026
04:13:31 PMFlip Answers |
| 1) | 402 * 398 = | | 1) 400 * 400 - 2 * 2 = 159996 |
| 2) | 398 * 402 = | | 2) 400 * 400 - 2 * 2 = 159996 |
| 3) | 202 * 198 = | | 3) 200 * 200 - 2 * 2 = 39996 |
| 4) | 110 * 90 = | | 4) 100 * 100 - 10 * 10 = 9900 |
| 5) | 110 * 90 = | | 5) 100 * 100 - 10 * 10 = 9900 |
| 6) | 195 * 205 = | | 6) 200 * 200 - 5 * 5 = 39975 |
| 7) | 299 * 301 = | | 7) 300 * 300 - 1 * 1 = 89999 |
| 8) | 394 * 406 = | | 8) 400 * 400 - 6 * 6 = 159964 |
| 9) | 401 * 399 = | | 9) 400 * 400 - 1 * 1 = 159999 |
| 10) | 398 * 402 = | | 10) 400 * 400 - 2 * 2 = 159996 |
| 11) | 81 * 272 - 81 * 72 = | | 11) ( 272 - 72) * 81 = 16200 |
| 12) | 59 * 79 + 79 * 41 = | | 12) ( 41 + 59) * 79 = 7900 |
| 13) | 68 * 274 - 68 * 74 = | | 13) ( 274 - 74) * 68 = 13600 |
| 14) | 41 * 43 + 157 * 41 = | | 14) ( 157 + 43) * 41 = 8200 |
| 15) | 60 * 55 + 40 * 55 = | | 15) ( 40 + 60) * 55 = 5500 |
| 16) | 173 * 90 - 90 * 73 = | | 16) ( 173 - 73) * 90 = 9000 |
| 17) | 48 * 39 + 61 * 48 = | | 17) ( 61 + 39) * 48 = 4800 |
| 18) | 90 * 145 + 55 * 90 = | | 18) ( 145 + 55) * 90 = 18000 |
| 19) | 35 * 58 + 165 * 58 = | | 19) ( 165 + 35) * 58 = 11600 |
| 20) | 29 * 33 + 67 * 29 = | | 20) ( 33 + 67) * 29 = 2900 |
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Score: ______________ | |
