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 04 2026
06:26:18 AM | Monday May 04 2026
06:26:18 AMFlip Answers |
| 1) | 391 * 409 = | | 1) 400 * 400 - 9 * 9 = 159919 |
| 2) | 199 * 201 = | | 2) 200 * 200 - 1 * 1 = 39999 |
| 3) | 409 * 391 = | | 3) 400 * 400 - 9 * 9 = 159919 |
| 4) | 92 * 108 = | | 4) 100 * 100 - 8 * 8 = 9936 |
| 5) | 101 * 99 = | | 5) 100 * 100 - 1 * 1 = 9999 |
| 6) | 410 * 390 = | | 6) 400 * 400 - 10 * 10 = 159900 |
| 7) | 94 * 106 = | | 7) 100 * 100 - 6 * 6 = 9964 |
| 8) | 291 * 309 = | | 8) 300 * 300 - 9 * 9 = 89919 |
| 9) | 399 * 401 = | | 9) 400 * 400 - 1 * 1 = 159999 |
| 10) | 107 * 93 = | | 10) 100 * 100 - 7 * 7 = 9951 |
| 11) | 74 * 150 + 50 * 74 = | | 11) ( 150 + 50) * 74 = 14800 |
| 12) | 48 * 81 + 52 * 81 = | | 12) ( 52 + 48) * 81 = 8100 |
| 13) | 159 * 47 - 47 * 59 = | | 13) ( 159 - 59) * 47 = 4700 |
| 14) | 58 * 40 + 40 * 42 = | | 14) ( 58 + 42) * 40 = 4000 |
| 15) | 246 * 42 - 46 * 42 = | | 15) ( 246 - 46) * 42 = 8400 |
| 16) | 148 * 56 - 48 * 56 = | | 16) ( 148 - 48) * 56 = 5600 |
| 17) | 258 * 31 - 58 * 31 = | | 17) ( 258 - 58) * 31 = 6200 |
| 18) | 143 * 88 + 88 * 57 = | | 18) ( 143 + 57) * 88 = 17600 |
| 19) | 251 * 25 - 51 * 25 = | | 19) ( 251 - 51) * 25 = 5000 |
| 20) | 93 * 136 - 36 * 93 = | | 20) ( 136 - 36) * 93 = 9300 |
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Score: ______________ | |
