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 May 01 2025
07:11:20 AM | Thursday May 01 2025
07:11:20 AMFlip Answers |
| 1) | 410 * 390 = | | 1) 400 * 400 - 10 * 10 = 159900 |
| 2) | 397 * 403 = | | 2) 400 * 400 - 3 * 3 = 159991 |
| 3) | 395 * 405 = | | 3) 400 * 400 - 5 * 5 = 159975 |
| 4) | 109 * 91 = | | 4) 100 * 100 - 9 * 9 = 9919 |
| 5) | 293 * 307 = | | 5) 300 * 300 - 7 * 7 = 89951 |
| 6) | 298 * 302 = | | 6) 300 * 300 - 2 * 2 = 89996 |
| 7) | 107 * 93 = | | 7) 100 * 100 - 7 * 7 = 9951 |
| 8) | 395 * 405 = | | 8) 400 * 400 - 5 * 5 = 159975 |
| 9) | 404 * 396 = | | 9) 400 * 400 - 4 * 4 = 159984 |
| 10) | 304 * 296 = | | 10) 300 * 300 - 4 * 4 = 89984 |
| 11) | 126 * 80 + 80 * 74 = | | 11) ( 126 + 74) * 80 = 16000 |
| 12) | 144 * 69 - 44 * 69 = | | 12) ( 144 - 44) * 69 = 6900 |
| 13) | 68 * 160 - 60 * 68 = | | 13) ( 160 - 60) * 68 = 6800 |
| 14) | 45 * 66 + 45 * 34 = | | 14) ( 34 + 66) * 45 = 4500 |
| 15) | 87 * 133 + 67 * 87 = | | 15) ( 133 + 67) * 87 = 17400 |
| 16) | 271 * 52 - 71 * 52 = | | 16) ( 271 - 71) * 52 = 10400 |
| 17) | 131 * 79 + 69 * 79 = | | 17) ( 131 + 69) * 79 = 15800 |
| 18) | 244 * 24 - 24 * 44 = | | 18) ( 244 - 44) * 24 = 4800 |
| 19) | 36 * 54 + 54 * 64 = | | 19) ( 64 + 36) * 54 = 5400 |
| 20) | 44 * 90 + 156 * 90 = | | 20) ( 156 + 44) * 90 = 18000 |
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Score: ______________ | |
