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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Thursday January 01 2026
02:30:06 PM | Thursday January 01 2026
02:30:06 PMFlip Answers |
| 1) | 197 * 203 = | | 1) 200 * 200 - 3 * 3 = 39991 |
| 2) | 410 * 390 = | | 2) 400 * 400 - 10 * 10 = 159900 |
| 3) | 309 * 291 = | | 3) 300 * 300 - 9 * 9 = 89919 |
| 4) | 103 * 97 = | | 4) 100 * 100 - 3 * 3 = 9991 |
| 5) | 108 * 92 = | | 5) 100 * 100 - 8 * 8 = 9936 |
| 6) | 96 * 104 = | | 6) 100 * 100 - 4 * 4 = 9984 |
| 7) | 99 * 101 = | | 7) 100 * 100 - 1 * 1 = 9999 |
| 8) | 103 * 97 = | | 8) 100 * 100 - 3 * 3 = 9991 |
| 9) | 394 * 406 = | | 9) 400 * 400 - 6 * 6 = 159964 |
| 10) | 106 * 94 = | | 10) 100 * 100 - 6 * 6 = 9964 |
| 11) | 66 * 61 + 66 * 39 = | | 11) ( 61 + 39) * 66 = 6600 |
| 12) | 77 * 171 - 77 * 71 = | | 12) ( 171 - 71) * 77 = 7700 |
| 13) | 28 * 165 - 65 * 28 = | | 13) ( 165 - 65) * 28 = 2800 |
| 14) | 69 * 44 + 31 * 44 = | | 14) ( 31 + 69) * 44 = 4400 |
| 15) | 77 * 157 + 43 * 77 = | | 15) ( 157 + 43) * 77 = 15400 |
| 16) | 90 * 237 - 37 * 90 = | | 16) ( 237 - 37) * 90 = 18000 |
| 17) | 248 * 87 - 48 * 87 = | | 17) ( 248 - 48) * 87 = 17400 |
| 18) | 246 * 58 - 58 * 46 = | | 18) ( 246 - 46) * 58 = 11600 |
| 19) | 44 * 155 - 44 * 55 = | | 19) ( 155 - 55) * 44 = 4400 |
| 20) | 135 * 42 - 35 * 42 = | | 20) ( 135 - 35) * 42 = 4200 |
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Score: ______________ | |
