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 August 02 2026
09:06:02 AM | Sunday August 02 2026
09:06:02 AMFlip Answers |
| 1) | 391 * 409 = | | 1) 400 * 400 - 9 * 9 = 159919 |
| 2) | 201 * 199 = | | 2) 200 * 200 - 1 * 1 = 39999 |
| 3) | 410 * 390 = | | 3) 400 * 400 - 10 * 10 = 159900 |
| 4) | 92 * 108 = | | 4) 100 * 100 - 8 * 8 = 9936 |
| 5) | 305 * 295 = | | 5) 300 * 300 - 5 * 5 = 89975 |
| 6) | 101 * 99 = | | 6) 100 * 100 - 1 * 1 = 9999 |
| 7) | 406 * 394 = | | 7) 400 * 400 - 6 * 6 = 159964 |
| 8) | 310 * 290 = | | 8) 300 * 300 - 10 * 10 = 89900 |
| 9) | 90 * 110 = | | 9) 100 * 100 - 10 * 10 = 9900 |
| 10) | 210 * 190 = | | 10) 200 * 200 - 10 * 10 = 39900 |
| 11) | 93 * 261 - 93 * 61 = | | 11) ( 261 - 61) * 93 = 18600 |
| 12) | 251 * 43 - 51 * 43 = | | 12) ( 251 - 51) * 43 = 8600 |
| 13) | 68 * 67 + 67 * 132 = | | 13) ( 132 + 68) * 67 = 13400 |
| 14) | 159 * 44 + 44 * 41 = | | 14) ( 159 + 41) * 44 = 8800 |
| 15) | 47 * 73 + 127 * 47 = | | 15) ( 127 + 73) * 47 = 9400 |
| 16) | 70 * 73 + 127 * 70 = | | 16) ( 127 + 73) * 70 = 14000 |
| 17) | 58 * 153 - 58 * 53 = | | 17) ( 153 - 53) * 58 = 5800 |
| 18) | 32 * 126 + 74 * 32 = | | 18) ( 126 + 74) * 32 = 6400 |
| 19) | 46 * 161 - 61 * 46 = | | 19) ( 161 - 61) * 46 = 4600 |
| 20) | 156 * 47 + 44 * 47 = | | 20) ( 156 + 44) * 47 = 9400 |
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Score: ______________ | |
