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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Tuesday April 14 2026
12:11:57 AM | Tuesday April 14 2026
12:11:57 AMFlip Answers |
| 1) | 99 * 101 = | | 1) 100 * 100 - 1 * 1 = 9999 |
| 2) | 392 * 408 = | | 2) 400 * 400 - 8 * 8 = 159936 |
| 3) | 110 * 90 = | | 3) 100 * 100 - 10 * 10 = 9900 |
| 4) | 196 * 204 = | | 4) 200 * 200 - 4 * 4 = 39984 |
| 5) | 395 * 405 = | | 5) 400 * 400 - 5 * 5 = 159975 |
| 6) | 409 * 391 = | | 6) 400 * 400 - 9 * 9 = 159919 |
| 7) | 103 * 97 = | | 7) 100 * 100 - 3 * 3 = 9991 |
| 8) | 93 * 107 = | | 8) 100 * 100 - 7 * 7 = 9951 |
| 9) | 398 * 402 = | | 9) 400 * 400 - 2 * 2 = 159996 |
| 10) | 395 * 405 = | | 10) 400 * 400 - 5 * 5 = 159975 |
| 11) | 165 * 53 + 53 * 35 = | | 11) ( 165 + 35) * 53 = 10600 |
| 12) | 74 * 164 - 74 * 64 = | | 12) ( 164 - 64) * 74 = 7400 |
| 13) | 162 * 22 - 62 * 22 = | | 13) ( 162 - 62) * 22 = 2200 |
| 14) | 80 * 268 - 68 * 80 = | | 14) ( 268 - 68) * 80 = 16000 |
| 15) | 94 * 255 - 94 * 55 = | | 15) ( 255 - 55) * 94 = 18800 |
| 16) | 45 * 66 + 66 * 55 = | | 16) ( 55 + 45) * 66 = 6600 |
| 17) | 58 * 257 - 58 * 57 = | | 17) ( 257 - 57) * 58 = 11600 |
| 18) | 42 * 256 - 56 * 42 = | | 18) ( 256 - 56) * 42 = 8400 |
| 19) | 33 * 138 - 38 * 33 = | | 19) ( 138 - 38) * 33 = 3300 |
| 20) | 42 * 142 + 42 * 58 = | | 20) ( 142 + 58) * 42 = 8400 |
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Score: ______________ | |
