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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Tuesday April 07 2026
01:35:05 AM | Tuesday April 07 2026
01:35:05 AMFlip Answers |
| 1) | 391 * 409 = | | 1) 400 * 400 - 9 * 9 = 159919 |
| 2) | 110 * 90 = | | 2) 100 * 100 - 10 * 10 = 9900 |
| 3) | 92 * 108 = | | 3) 100 * 100 - 8 * 8 = 9936 |
| 4) | 409 * 391 = | | 4) 400 * 400 - 9 * 9 = 159919 |
| 5) | 310 * 290 = | | 5) 300 * 300 - 10 * 10 = 89900 |
| 6) | 402 * 398 = | | 6) 400 * 400 - 2 * 2 = 159996 |
| 7) | 109 * 91 = | | 7) 100 * 100 - 9 * 9 = 9919 |
| 8) | 196 * 204 = | | 8) 200 * 200 - 4 * 4 = 39984 |
| 9) | 410 * 390 = | | 9) 400 * 400 - 10 * 10 = 159900 |
| 10) | 105 * 95 = | | 10) 100 * 100 - 5 * 5 = 9975 |
| 11) | 63 * 55 + 63 * 145 = | | 11) ( 145 + 55) * 63 = 12600 |
| 12) | 59 * 41 + 59 * 59 = | | 12) ( 59 + 41) * 59 = 5900 |
| 13) | 39 * 77 + 77 * 161 = | | 13) ( 161 + 39) * 77 = 15400 |
| 14) | 43 * 170 - 70 * 43 = | | 14) ( 170 - 70) * 43 = 4300 |
| 15) | 36 * 135 - 35 * 36 = | | 15) ( 135 - 35) * 36 = 3600 |
| 16) | 275 * 85 - 75 * 85 = | | 16) ( 275 - 75) * 85 = 17000 |
| 17) | 237 * 70 - 70 * 37 = | | 17) ( 237 - 37) * 70 = 14000 |
| 18) | 55 * 50 + 55 * 50 = | | 18) ( 50 + 50) * 55 = 5500 |
| 19) | 45 * 174 - 74 * 45 = | | 19) ( 174 - 74) * 45 = 4500 |
| 20) | 44 * 256 - 44 * 56 = | | 20) ( 256 - 56) * 44 = 8800 |
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Score: ______________ | |
