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 August 11 2026
01:57:13 PM | Tuesday August 11 2026
01:57:13 PMFlip Answers |
| 1) | 309 * 291 = | | 1) 300 * 300 - 9 * 9 = 89919 |
| 2) | 409 * 391 = | | 2) 400 * 400 - 9 * 9 = 159919 |
| 3) | 392 * 408 = | | 3) 400 * 400 - 8 * 8 = 159936 |
| 4) | 409 * 391 = | | 4) 400 * 400 - 9 * 9 = 159919 |
| 5) | 205 * 195 = | | 5) 200 * 200 - 5 * 5 = 39975 |
| 6) | 404 * 396 = | | 6) 400 * 400 - 4 * 4 = 159984 |
| 7) | 110 * 90 = | | 7) 100 * 100 - 10 * 10 = 9900 |
| 8) | 103 * 97 = | | 8) 100 * 100 - 3 * 3 = 9991 |
| 9) | 109 * 91 = | | 9) 100 * 100 - 9 * 9 = 9919 |
| 10) | 95 * 105 = | | 10) 100 * 100 - 5 * 5 = 9975 |
| 11) | 63 * 49 + 37 * 49 = | | 11) ( 63 + 37) * 49 = 4900 |
| 12) | 59 * 35 + 59 * 65 = | | 12) ( 65 + 35) * 59 = 5900 |
| 13) | 62 * 56 + 38 * 56 = | | 13) ( 62 + 38) * 56 = 5600 |
| 14) | 35 * 175 - 35 * 75 = | | 14) ( 175 - 75) * 35 = 3500 |
| 15) | 148 * 59 + 59 * 52 = | | 15) ( 148 + 52) * 59 = 11800 |
| 16) | 240 * 42 - 40 * 42 = | | 16) ( 240 - 40) * 42 = 8400 |
| 17) | 30 * 170 - 70 * 30 = | | 17) ( 170 - 70) * 30 = 3000 |
| 18) | 82 * 62 + 38 * 82 = | | 18) ( 62 + 38) * 82 = 8200 |
| 19) | 78 * 162 + 78 * 38 = | | 19) ( 162 + 38) * 78 = 15600 |
| 20) | 30 * 269 - 69 * 30 = | | 20) ( 269 - 69) * 30 = 6000 |
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Score: ______________ | |
