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 September 13 2026
10:34:43 PM | Sunday September 13 2026
10:34:43 PMFlip Answers |
| 1) | 291 * 309 = | | 1) 300 * 300 - 9 * 9 = 89919 |
| 2) | 198 * 202 = | | 2) 200 * 200 - 2 * 2 = 39996 |
| 3) | 410 * 390 = | | 3) 400 * 400 - 10 * 10 = 159900 |
| 4) | 204 * 196 = | | 4) 200 * 200 - 4 * 4 = 39984 |
| 5) | 410 * 390 = | | 5) 400 * 400 - 10 * 10 = 159900 |
| 6) | 296 * 304 = | | 6) 300 * 300 - 4 * 4 = 89984 |
| 7) | 310 * 290 = | | 7) 300 * 300 - 10 * 10 = 89900 |
| 8) | 310 * 290 = | | 8) 300 * 300 - 10 * 10 = 89900 |
| 9) | 209 * 191 = | | 9) 200 * 200 - 9 * 9 = 39919 |
| 10) | 207 * 193 = | | 10) 200 * 200 - 7 * 7 = 39951 |
| 11) | 66 * 133 + 66 * 67 = | | 11) ( 133 + 67) * 66 = 13200 |
| 12) | 94 * 164 - 94 * 64 = | | 12) ( 164 - 64) * 94 = 9400 |
| 13) | 50 * 141 - 41 * 50 = | | 13) ( 141 - 41) * 50 = 5000 |
| 14) | 267 * 68 - 68 * 67 = | | 14) ( 267 - 67) * 68 = 13600 |
| 15) | 34 * 65 + 34 * 35 = | | 15) ( 35 + 65) * 34 = 3400 |
| 16) | 76 * 147 - 76 * 47 = | | 16) ( 147 - 47) * 76 = 7600 |
| 17) | 78 * 63 + 78 * 137 = | | 17) ( 137 + 63) * 78 = 15600 |
| 18) | 24 * 136 - 36 * 24 = | | 18) ( 136 - 36) * 24 = 2400 |
| 19) | 48 * 50 + 52 * 50 = | | 19) ( 52 + 48) * 50 = 5000 |
| 20) | 33 * 155 + 33 * 45 = | | 20) ( 155 + 45) * 33 = 6600 |
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Score: ______________ | |
