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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Monday May 11 2026
06:50:02 PM | Monday May 11 2026
06:50:02 PMFlip Answers |
| 1) | 109 * 91 = | | 1) 100 * 100 - 9 * 9 = 9919 |
| 2) | 204 * 196 = | | 2) 200 * 200 - 4 * 4 = 39984 |
| 3) | 303 * 297 = | | 3) 300 * 300 - 3 * 3 = 89991 |
| 4) | 98 * 102 = | | 4) 100 * 100 - 2 * 2 = 9996 |
| 5) | 197 * 203 = | | 5) 200 * 200 - 3 * 3 = 39991 |
| 6) | 393 * 407 = | | 6) 400 * 400 - 7 * 7 = 159951 |
| 7) | 98 * 102 = | | 7) 100 * 100 - 2 * 2 = 9996 |
| 8) | 297 * 303 = | | 8) 300 * 300 - 3 * 3 = 89991 |
| 9) | 101 * 99 = | | 9) 100 * 100 - 1 * 1 = 9999 |
| 10) | 292 * 308 = | | 10) 300 * 300 - 8 * 8 = 89936 |
| 11) | 58 * 82 + 42 * 82 = | | 11) ( 42 + 58) * 82 = 8200 |
| 12) | 146 * 31 - 46 * 31 = | | 12) ( 146 - 46) * 31 = 3100 |
| 13) | 94 * 52 + 48 * 94 = | | 13) ( 52 + 48) * 94 = 9400 |
| 14) | 42 * 70 + 70 * 158 = | | 14) ( 158 + 42) * 70 = 14000 |
| 15) | 28 * 171 - 71 * 28 = | | 15) ( 171 - 71) * 28 = 2800 |
| 16) | 76 * 142 - 76 * 42 = | | 16) ( 142 - 42) * 76 = 7600 |
| 17) | 58 * 92 + 92 * 42 = | | 17) ( 42 + 58) * 92 = 9200 |
| 18) | 86 * 26 + 74 * 86 = | | 18) ( 26 + 74) * 86 = 8600 |
| 19) | 50 * 261 - 50 * 61 = | | 19) ( 261 - 61) * 50 = 10000 |
| 20) | 65 * 49 + 65 * 51 = | | 20) ( 49 + 51) * 65 = 6500 |
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Score: ______________ | |
