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 February 08 2026
06:04:15 AM | Sunday February 08 2026
06:04:15 AMFlip Answers |
| 1) | 209 * 191 = | | 1) 200 * 200 - 9 * 9 = 39919 |
| 2) | 106 * 94 = | | 2) 100 * 100 - 6 * 6 = 9964 |
| 3) | 97 * 103 = | | 3) 100 * 100 - 3 * 3 = 9991 |
| 4) | 393 * 407 = | | 4) 400 * 400 - 7 * 7 = 159951 |
| 5) | 203 * 197 = | | 5) 200 * 200 - 3 * 3 = 39991 |
| 6) | 310 * 290 = | | 6) 300 * 300 - 10 * 10 = 89900 |
| 7) | 98 * 102 = | | 7) 100 * 100 - 2 * 2 = 9996 |
| 8) | 309 * 291 = | | 8) 300 * 300 - 9 * 9 = 89919 |
| 9) | 395 * 405 = | | 9) 400 * 400 - 5 * 5 = 159975 |
| 10) | 393 * 407 = | | 10) 400 * 400 - 7 * 7 = 159951 |
| 11) | 157 * 29 - 57 * 29 = | | 11) ( 157 - 57) * 29 = 2900 |
| 12) | 42 * 258 - 58 * 42 = | | 12) ( 258 - 58) * 42 = 8400 |
| 13) | 72 * 235 - 72 * 35 = | | 13) ( 235 - 35) * 72 = 14400 |
| 14) | 24 * 45 + 155 * 24 = | | 14) ( 155 + 45) * 24 = 4800 |
| 15) | 272 * 81 - 81 * 72 = | | 15) ( 272 - 72) * 81 = 16200 |
| 16) | 67 * 158 - 58 * 67 = | | 16) ( 158 - 58) * 67 = 6700 |
| 17) | 275 * 39 - 75 * 39 = | | 17) ( 275 - 75) * 39 = 7800 |
| 18) | 274 * 53 - 74 * 53 = | | 18) ( 274 - 74) * 53 = 10600 |
| 19) | 141 * 53 - 53 * 41 = | | 19) ( 141 - 41) * 53 = 5300 |
| 20) | 165 * 37 - 65 * 37 = | | 20) ( 165 - 65) * 37 = 3700 |
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Score: ______________ | |
