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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Friday April 10 2026
11:43:53 PM | Friday April 10 2026
11:43:53 PMFlip Answers |
| 1) | 101 * 99 = | | 1) 100 * 100 - 1 * 1 = 9999 |
| 2) | 103 * 97 = | | 2) 100 * 100 - 3 * 3 = 9991 |
| 3) | 109 * 91 = | | 3) 100 * 100 - 9 * 9 = 9919 |
| 4) | 402 * 398 = | | 4) 400 * 400 - 2 * 2 = 159996 |
| 5) | 395 * 405 = | | 5) 400 * 400 - 5 * 5 = 159975 |
| 6) | 193 * 207 = | | 6) 200 * 200 - 7 * 7 = 39951 |
| 7) | 198 * 202 = | | 7) 200 * 200 - 2 * 2 = 39996 |
| 8) | 190 * 210 = | | 8) 200 * 200 - 10 * 10 = 39900 |
| 9) | 104 * 96 = | | 9) 100 * 100 - 4 * 4 = 9984 |
| 10) | 409 * 391 = | | 10) 400 * 400 - 9 * 9 = 159919 |
| 11) | 159 * 71 - 59 * 71 = | | 11) ( 159 - 59) * 71 = 7100 |
| 12) | 56 * 67 + 44 * 67 = | | 12) ( 56 + 44) * 67 = 6700 |
| 13) | 161 * 79 - 61 * 79 = | | 13) ( 161 - 61) * 79 = 7900 |
| 14) | 139 * 85 + 61 * 85 = | | 14) ( 139 + 61) * 85 = 17000 |
| 15) | 254 * 64 - 54 * 64 = | | 15) ( 254 - 54) * 64 = 12800 |
| 16) | 271 * 75 - 71 * 75 = | | 16) ( 271 - 71) * 75 = 15000 |
| 17) | 60 * 42 + 40 * 42 = | | 17) ( 60 + 40) * 42 = 4200 |
| 18) | 58 * 46 + 58 * 154 = | | 18) ( 154 + 46) * 58 = 11600 |
| 19) | 73 * 57 + 43 * 73 = | | 19) ( 43 + 57) * 73 = 7300 |
| 20) | 166 * 94 - 94 * 66 = | | 20) ( 166 - 66) * 94 = 9400 |
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Score: ______________ | |
