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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Sunday May 10 2026
03:53:17 PM | Sunday May 10 2026
03:53:17 PMFlip Answers |
| 1) | 404 * 396 = | | 1) 400 * 400 - 4 * 4 = 159984 |
| 2) | 295 * 305 = | | 2) 300 * 300 - 5 * 5 = 89975 |
| 3) | 97 * 103 = | | 3) 100 * 100 - 3 * 3 = 9991 |
| 4) | 90 * 110 = | | 4) 100 * 100 - 10 * 10 = 9900 |
| 5) | 209 * 191 = | | 5) 200 * 200 - 9 * 9 = 39919 |
| 6) | 391 * 409 = | | 6) 400 * 400 - 9 * 9 = 159919 |
| 7) | 302 * 298 = | | 7) 300 * 300 - 2 * 2 = 89996 |
| 8) | 198 * 202 = | | 8) 200 * 200 - 2 * 2 = 39996 |
| 9) | 408 * 392 = | | 9) 400 * 400 - 8 * 8 = 159936 |
| 10) | 202 * 198 = | | 10) 200 * 200 - 2 * 2 = 39996 |
| 11) | 64 * 35 + 36 * 35 = | | 11) ( 36 + 64) * 35 = 3500 |
| 12) | 71 * 26 + 129 * 26 = | | 12) ( 129 + 71) * 26 = 5200 |
| 13) | 62 * 160 - 60 * 62 = | | 13) ( 160 - 60) * 62 = 6200 |
| 14) | 31 * 68 + 31 * 32 = | | 14) ( 32 + 68) * 31 = 3100 |
| 15) | 72 * 84 + 84 * 28 = | | 15) ( 28 + 72) * 84 = 8400 |
| 16) | 135 * 43 - 43 * 35 = | | 16) ( 135 - 35) * 43 = 4300 |
| 17) | 40 * 152 - 52 * 40 = | | 17) ( 152 - 52) * 40 = 4000 |
| 18) | 78 * 238 - 38 * 78 = | | 18) ( 238 - 38) * 78 = 15600 |
| 19) | 76 * 46 + 54 * 76 = | | 19) ( 54 + 46) * 76 = 7600 |
| 20) | 58 * 126 + 58 * 74 = | | 20) ( 126 + 74) * 58 = 11600 |
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Score: ______________ | |
