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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Monday July 20 2026
03:40:45 PM | Monday July 20 2026
03:40:45 PMFlip Answers |
| 1) | 210 * 190 = | | 1) 200 * 200 - 10 * 10 = 39900 |
| 2) | 401 * 399 = | | 2) 400 * 400 - 1 * 1 = 159999 |
| 3) | 208 * 192 = | | 3) 200 * 200 - 8 * 8 = 39936 |
| 4) | 92 * 108 = | | 4) 100 * 100 - 8 * 8 = 9936 |
| 5) | 93 * 107 = | | 5) 100 * 100 - 7 * 7 = 9951 |
| 6) | 107 * 93 = | | 6) 100 * 100 - 7 * 7 = 9951 |
| 7) | 109 * 91 = | | 7) 100 * 100 - 9 * 9 = 9919 |
| 8) | 403 * 397 = | | 8) 400 * 400 - 3 * 3 = 159991 |
| 9) | 102 * 98 = | | 9) 100 * 100 - 2 * 2 = 9996 |
| 10) | 293 * 307 = | | 10) 300 * 300 - 7 * 7 = 89951 |
| 11) | 52 * 64 + 148 * 64 = | | 11) ( 148 + 52) * 64 = 12800 |
| 12) | 84 * 150 + 84 * 50 = | | 12) ( 150 + 50) * 84 = 16800 |
| 13) | 58 * 44 + 44 * 42 = | | 13) ( 42 + 58) * 44 = 4400 |
| 14) | 56 * 91 + 91 * 44 = | | 14) ( 56 + 44) * 91 = 9100 |
| 15) | 87 * 163 + 87 * 37 = | | 15) ( 163 + 37) * 87 = 17400 |
| 16) | 94 * 63 + 94 * 137 = | | 16) ( 137 + 63) * 94 = 18800 |
| 17) | 57 * 86 + 43 * 86 = | | 17) ( 57 + 43) * 86 = 8600 |
| 18) | 44 * 48 + 48 * 56 = | | 18) ( 56 + 44) * 48 = 4800 |
| 19) | 81 * 242 - 81 * 42 = | | 19) ( 242 - 42) * 81 = 16200 |
| 20) | 169 * 37 - 69 * 37 = | | 20) ( 169 - 69) * 37 = 3700 |
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Score: ______________ | |
