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 January 01 2026
06:48:39 AM | Thursday January 01 2026
06:48:39 AMFlip Answers |
| 1) | 305 * 295 = | | 1) 300 * 300 - 5 * 5 = 89975 |
| 2) | 295 * 305 = | | 2) 300 * 300 - 5 * 5 = 89975 |
| 3) | 391 * 409 = | | 3) 400 * 400 - 9 * 9 = 159919 |
| 4) | 190 * 210 = | | 4) 200 * 200 - 10 * 10 = 39900 |
| 5) | 390 * 410 = | | 5) 400 * 400 - 10 * 10 = 159900 |
| 6) | 299 * 301 = | | 6) 300 * 300 - 1 * 1 = 89999 |
| 7) | 91 * 109 = | | 7) 100 * 100 - 9 * 9 = 9919 |
| 8) | 201 * 199 = | | 8) 200 * 200 - 1 * 1 = 39999 |
| 9) | 90 * 110 = | | 9) 100 * 100 - 10 * 10 = 9900 |
| 10) | 292 * 308 = | | 10) 300 * 300 - 8 * 8 = 89936 |
| 11) | 270 * 92 - 92 * 70 = | | 11) ( 270 - 70) * 92 = 18400 |
| 12) | 66 * 154 - 54 * 66 = | | 12) ( 154 - 54) * 66 = 6600 |
| 13) | 78 * 41 + 78 * 59 = | | 13) ( 41 + 59) * 78 = 7800 |
| 14) | 247 * 32 - 47 * 32 = | | 14) ( 247 - 47) * 32 = 6400 |
| 15) | 272 * 54 - 54 * 72 = | | 15) ( 272 - 72) * 54 = 10800 |
| 16) | 75 * 171 - 75 * 71 = | | 16) ( 171 - 71) * 75 = 7500 |
| 17) | 73 * 81 + 127 * 81 = | | 17) ( 127 + 73) * 81 = 16200 |
| 18) | 46 * 21 + 54 * 21 = | | 18) ( 54 + 46) * 21 = 2100 |
| 19) | 60 * 58 + 58 * 40 = | | 19) ( 60 + 40) * 58 = 5800 |
| 20) | 78 * 145 + 55 * 78 = | | 20) ( 145 + 55) * 78 = 15600 |
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Score: ______________ | |
