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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Sunday December 28 2025
07:12:17 PM | Sunday December 28 2025
07:12:17 PMFlip Answers |
| 1) | 190 * 210 = | | 1) 200 * 200 - 10 * 10 = 39900 |
| 2) | 194 * 206 = | | 2) 200 * 200 - 6 * 6 = 39964 |
| 3) | 102 * 98 = | | 3) 100 * 100 - 2 * 2 = 9996 |
| 4) | 199 * 201 = | | 4) 200 * 200 - 1 * 1 = 39999 |
| 5) | 405 * 395 = | | 5) 400 * 400 - 5 * 5 = 159975 |
| 6) | 198 * 202 = | | 6) 200 * 200 - 2 * 2 = 39996 |
| 7) | 301 * 299 = | | 7) 300 * 300 - 1 * 1 = 89999 |
| 8) | 406 * 394 = | | 8) 400 * 400 - 6 * 6 = 159964 |
| 9) | 408 * 392 = | | 9) 400 * 400 - 8 * 8 = 159936 |
| 10) | 406 * 394 = | | 10) 400 * 400 - 6 * 6 = 159964 |
| 11) | 37 * 175 - 37 * 75 = | | 11) ( 175 - 75) * 37 = 3700 |
| 12) | 29 * 62 + 29 * 138 = | | 12) ( 138 + 62) * 29 = 5800 |
| 13) | 64 * 62 + 36 * 62 = | | 13) ( 36 + 64) * 62 = 6200 |
| 14) | 81 * 46 + 54 * 81 = | | 14) ( 46 + 54) * 81 = 8100 |
| 15) | 25 * 50 + 25 * 50 = | | 15) ( 50 + 50) * 25 = 2500 |
| 16) | 61 * 65 + 35 * 61 = | | 16) ( 65 + 35) * 61 = 6100 |
| 17) | 74 * 63 + 63 * 26 = | | 17) ( 26 + 74) * 63 = 6300 |
| 18) | 44 * 57 + 143 * 44 = | | 18) ( 143 + 57) * 44 = 8800 |
| 19) | 39 * 31 + 61 * 31 = | | 19) ( 61 + 39) * 31 = 3100 |
| 20) | 47 * 44 + 53 * 44 = | | 20) ( 53 + 47) * 44 = 4400 |
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Score: ______________ | |
