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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Wednesday May 13 2026
10:40:06 PM | Wednesday May 13 2026
10:40:06 PMFlip Answers |
| 1) | 110 * 90 = | | 1) 100 * 100 - 10 * 10 = 9900 |
| 2) | 402 * 398 = | | 2) 400 * 400 - 2 * 2 = 159996 |
| 3) | 398 * 402 = | | 3) 400 * 400 - 2 * 2 = 159996 |
| 4) | 402 * 398 = | | 4) 400 * 400 - 2 * 2 = 159996 |
| 5) | 302 * 298 = | | 5) 300 * 300 - 2 * 2 = 89996 |
| 6) | 405 * 395 = | | 6) 400 * 400 - 5 * 5 = 159975 |
| 7) | 101 * 99 = | | 7) 100 * 100 - 1 * 1 = 9999 |
| 8) | 391 * 409 = | | 8) 400 * 400 - 9 * 9 = 159919 |
| 9) | 201 * 199 = | | 9) 200 * 200 - 1 * 1 = 39999 |
| 10) | 295 * 305 = | | 10) 300 * 300 - 5 * 5 = 89975 |
| 11) | 22 * 125 + 22 * 75 = | | 11) ( 125 + 75) * 22 = 4400 |
| 12) | 27 * 55 + 55 * 73 = | | 12) ( 27 + 73) * 55 = 5500 |
| 13) | 163 * 33 + 37 * 33 = | | 13) ( 163 + 37) * 33 = 6600 |
| 14) | 143 * 37 + 37 * 57 = | | 14) ( 143 + 57) * 37 = 7400 |
| 15) | 262 * 81 - 62 * 81 = | | 15) ( 262 - 62) * 81 = 16200 |
| 16) | 69 * 42 + 69 * 58 = | | 16) ( 58 + 42) * 69 = 6900 |
| 17) | 138 * 59 - 38 * 59 = | | 17) ( 138 - 38) * 59 = 5900 |
| 18) | 142 * 73 - 73 * 42 = | | 18) ( 142 - 42) * 73 = 7300 |
| 19) | 35 * 94 + 94 * 65 = | | 19) ( 65 + 35) * 94 = 9400 |
| 20) | 71 * 239 - 39 * 71 = | | 20) ( 239 - 39) * 71 = 14200 |
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Score: ______________ | |
