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 March 05 2026
06:15:06 PM | Thursday March 05 2026
06:15:06 PMFlip Answers |
| 1) | 209 * 191 = | | 1) 200 * 200 - 9 * 9 = 39919 |
| 2) | 398 * 402 = | | 2) 400 * 400 - 2 * 2 = 159996 |
| 3) | 191 * 209 = | | 3) 200 * 200 - 9 * 9 = 39919 |
| 4) | 103 * 97 = | | 4) 100 * 100 - 3 * 3 = 9991 |
| 5) | 299 * 301 = | | 5) 300 * 300 - 1 * 1 = 89999 |
| 6) | 105 * 95 = | | 6) 100 * 100 - 5 * 5 = 9975 |
| 7) | 99 * 101 = | | 7) 100 * 100 - 1 * 1 = 9999 |
| 8) | 392 * 408 = | | 8) 400 * 400 - 8 * 8 = 159936 |
| 9) | 290 * 310 = | | 9) 300 * 300 - 10 * 10 = 89900 |
| 10) | 197 * 203 = | | 10) 200 * 200 - 3 * 3 = 39991 |
| 11) | 129 * 62 + 71 * 62 = | | 11) ( 129 + 71) * 62 = 12400 |
| 12) | 25 * 65 + 135 * 25 = | | 12) ( 135 + 65) * 25 = 5000 |
| 13) | 61 * 31 + 61 * 69 = | | 13) ( 31 + 69) * 61 = 6100 |
| 14) | 270 * 46 - 46 * 70 = | | 14) ( 270 - 70) * 46 = 9200 |
| 15) | 155 * 76 - 76 * 55 = | | 15) ( 155 - 55) * 76 = 7600 |
| 16) | 76 * 161 - 76 * 61 = | | 16) ( 161 - 61) * 76 = 7600 |
| 17) | 244 * 60 - 60 * 44 = | | 17) ( 244 - 44) * 60 = 12000 |
| 18) | 72 * 163 - 63 * 72 = | | 18) ( 163 - 63) * 72 = 7200 |
| 19) | 65 * 36 + 36 * 135 = | | 19) ( 135 + 65) * 36 = 7200 |
| 20) | 36 * 141 - 36 * 41 = | | 20) ( 141 - 41) * 36 = 3600 |
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Score: ______________ | |
