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 June 14 2026
01:16:30 AM | Sunday June 14 2026
01:16:30 AMFlip Answers |
| 1) | 97 * 103 = | | 1) 100 * 100 - 3 * 3 = 9991 |
| 2) | 402 * 398 = | | 2) 400 * 400 - 2 * 2 = 159996 |
| 3) | 190 * 210 = | | 3) 200 * 200 - 10 * 10 = 39900 |
| 4) | 90 * 110 = | | 4) 100 * 100 - 10 * 10 = 9900 |
| 5) | 99 * 101 = | | 5) 100 * 100 - 1 * 1 = 9999 |
| 6) | 410 * 390 = | | 6) 400 * 400 - 10 * 10 = 159900 |
| 7) | 405 * 395 = | | 7) 400 * 400 - 5 * 5 = 159975 |
| 8) | 201 * 199 = | | 8) 200 * 200 - 1 * 1 = 39999 |
| 9) | 409 * 391 = | | 9) 400 * 400 - 9 * 9 = 159919 |
| 10) | 210 * 190 = | | 10) 200 * 200 - 10 * 10 = 39900 |
| 11) | 162 * 36 - 62 * 36 = | | 11) ( 162 - 62) * 36 = 3600 |
| 12) | 88 * 72 + 88 * 128 = | | 12) ( 128 + 72) * 88 = 17600 |
| 13) | 268 * 74 - 68 * 74 = | | 13) ( 268 - 68) * 74 = 14800 |
| 14) | 142 * 34 - 34 * 42 = | | 14) ( 142 - 42) * 34 = 3400 |
| 15) | 61 * 153 - 61 * 53 = | | 15) ( 153 - 53) * 61 = 6100 |
| 16) | 42 * 21 + 21 * 158 = | | 16) ( 158 + 42) * 21 = 4200 |
| 17) | 94 * 156 - 56 * 94 = | | 17) ( 156 - 56) * 94 = 9400 |
| 18) | 66 * 89 + 34 * 89 = | | 18) ( 34 + 66) * 89 = 8900 |
| 19) | 255 * 82 - 82 * 55 = | | 19) ( 255 - 55) * 82 = 16400 |
| 20) | 273 * 42 - 73 * 42 = | | 20) ( 273 - 73) * 42 = 8400 |
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Score: ______________ | |
