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 October 23 2026
06:10:29 AM | Friday October 23 2026
06:10:29 AMFlip Answers |
| 1) | 390 * 410 = | | 1) 400 * 400 - 10 * 10 = 159900 |
| 2) | 209 * 191 = | | 2) 200 * 200 - 9 * 9 = 39919 |
| 3) | 102 * 98 = | | 3) 100 * 100 - 2 * 2 = 9996 |
| 4) | 303 * 297 = | | 4) 300 * 300 - 3 * 3 = 89991 |
| 5) | 303 * 297 = | | 5) 300 * 300 - 3 * 3 = 89991 |
| 6) | 90 * 110 = | | 6) 100 * 100 - 10 * 10 = 9900 |
| 7) | 395 * 405 = | | 7) 400 * 400 - 5 * 5 = 159975 |
| 8) | 210 * 190 = | | 8) 200 * 200 - 10 * 10 = 39900 |
| 9) | 195 * 205 = | | 9) 200 * 200 - 5 * 5 = 39975 |
| 10) | 396 * 404 = | | 10) 400 * 400 - 4 * 4 = 159984 |
| 11) | 94 * 36 + 164 * 94 = | | 11) ( 164 + 36) * 94 = 18800 |
| 12) | 41 * 267 - 67 * 41 = | | 12) ( 267 - 67) * 41 = 8200 |
| 13) | 26 * 261 - 61 * 26 = | | 13) ( 261 - 61) * 26 = 5200 |
| 14) | 80 * 265 - 65 * 80 = | | 14) ( 265 - 65) * 80 = 16000 |
| 15) | 261 * 82 - 61 * 82 = | | 15) ( 261 - 61) * 82 = 16400 |
| 16) | 159 * 62 - 59 * 62 = | | 16) ( 159 - 59) * 62 = 6200 |
| 17) | 97 * 60 + 140 * 97 = | | 17) ( 140 + 60) * 97 = 19400 |
| 18) | 41 * 26 + 26 * 159 = | | 18) ( 159 + 41) * 26 = 5200 |
| 19) | 41 * 48 + 48 * 59 = | | 19) ( 41 + 59) * 48 = 4800 |
| 20) | 21 * 52 + 21 * 48 = | | 20) ( 52 + 48) * 21 = 2100 |
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Score: ______________ | |
