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 May 31 2026
02:09:55 PM | Sunday May 31 2026
02:09:55 PMFlip Answers |
| 1) | 110 * 90 = | | 1) 100 * 100 - 10 * 10 = 9900 |
| 2) | 90 * 110 = | | 2) 100 * 100 - 10 * 10 = 9900 |
| 3) | 393 * 407 = | | 3) 400 * 400 - 7 * 7 = 159951 |
| 4) | 290 * 310 = | | 4) 300 * 300 - 10 * 10 = 89900 |
| 5) | 203 * 197 = | | 5) 200 * 200 - 3 * 3 = 39991 |
| 6) | 108 * 92 = | | 6) 100 * 100 - 8 * 8 = 9936 |
| 7) | 398 * 402 = | | 7) 400 * 400 - 2 * 2 = 159996 |
| 8) | 105 * 95 = | | 8) 100 * 100 - 5 * 5 = 9975 |
| 9) | 290 * 310 = | | 9) 300 * 300 - 10 * 10 = 89900 |
| 10) | 101 * 99 = | | 10) 100 * 100 - 1 * 1 = 9999 |
| 11) | 52 * 31 + 48 * 31 = | | 11) ( 48 + 52) * 31 = 3100 |
| 12) | 56 * 97 + 97 * 144 = | | 12) ( 144 + 56) * 97 = 19400 |
| 13) | 151 * 84 + 49 * 84 = | | 13) ( 151 + 49) * 84 = 16800 |
| 14) | 87 * 66 + 134 * 87 = | | 14) ( 134 + 66) * 87 = 17400 |
| 15) | 42 * 39 + 58 * 39 = | | 15) ( 58 + 42) * 39 = 3900 |
| 16) | 26 * 41 + 59 * 26 = | | 16) ( 41 + 59) * 26 = 2600 |
| 17) | 68 * 79 + 79 * 132 = | | 17) ( 132 + 68) * 79 = 15800 |
| 18) | 28 * 248 - 48 * 28 = | | 18) ( 248 - 48) * 28 = 5600 |
| 19) | 58 * 72 + 58 * 128 = | | 19) ( 128 + 72) * 58 = 11600 |
| 20) | 82 * 41 + 59 * 82 = | | 20) ( 59 + 41) * 82 = 8200 |
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Score: ______________ | |
