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 January 11 2026
01:55:40 PM | Sunday January 11 2026
01:55:40 PMFlip Answers |
| 1) | 397 * 403 = | | 1) 400 * 400 - 3 * 3 = 159991 |
| 2) | 290 * 310 = | | 2) 300 * 300 - 10 * 10 = 89900 |
| 3) | 392 * 408 = | | 3) 400 * 400 - 8 * 8 = 159936 |
| 4) | 404 * 396 = | | 4) 400 * 400 - 4 * 4 = 159984 |
| 5) | 97 * 103 = | | 5) 100 * 100 - 3 * 3 = 9991 |
| 6) | 199 * 201 = | | 6) 200 * 200 - 1 * 1 = 39999 |
| 7) | 110 * 90 = | | 7) 100 * 100 - 10 * 10 = 9900 |
| 8) | 307 * 293 = | | 8) 300 * 300 - 7 * 7 = 89951 |
| 9) | 105 * 95 = | | 9) 100 * 100 - 5 * 5 = 9975 |
| 10) | 205 * 195 = | | 10) 200 * 200 - 5 * 5 = 39975 |
| 11) | 75 * 73 + 27 * 75 = | | 11) ( 27 + 73) * 75 = 7500 |
| 12) | 136 * 79 + 79 * 64 = | | 12) ( 136 + 64) * 79 = 15800 |
| 13) | 137 * 75 - 75 * 37 = | | 13) ( 137 - 37) * 75 = 7500 |
| 14) | 154 * 38 + 46 * 38 = | | 14) ( 154 + 46) * 38 = 7600 |
| 15) | 41 * 133 + 67 * 41 = | | 15) ( 133 + 67) * 41 = 8200 |
| 16) | 68 * 172 - 72 * 68 = | | 16) ( 172 - 72) * 68 = 6800 |
| 17) | 56 * 149 - 49 * 56 = | | 17) ( 149 - 49) * 56 = 5600 |
| 18) | 56 * 50 + 44 * 50 = | | 18) ( 56 + 44) * 50 = 5000 |
| 19) | 258 * 25 - 25 * 58 = | | 19) ( 258 - 58) * 25 = 5000 |
| 20) | 157 * 29 - 57 * 29 = | | 20) ( 157 - 57) * 29 = 2900 |
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Score: ______________ | |
