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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Friday November 13 2026
05:14:15 PM | Friday November 13 2026
05:14:15 PMFlip Answers |
| 1) | 310 * 290 = | | 1) 300 * 300 - 10 * 10 = 89900 |
| 2) | 290 * 310 = | | 2) 300 * 300 - 10 * 10 = 89900 |
| 3) | 396 * 404 = | | 3) 400 * 400 - 4 * 4 = 159984 |
| 4) | 403 * 397 = | | 4) 400 * 400 - 3 * 3 = 159991 |
| 5) | 395 * 405 = | | 5) 400 * 400 - 5 * 5 = 159975 |
| 6) | 302 * 298 = | | 6) 300 * 300 - 2 * 2 = 89996 |
| 7) | 396 * 404 = | | 7) 400 * 400 - 4 * 4 = 159984 |
| 8) | 191 * 209 = | | 8) 200 * 200 - 9 * 9 = 39919 |
| 9) | 203 * 197 = | | 9) 200 * 200 - 3 * 3 = 39991 |
| 10) | 110 * 90 = | | 10) 100 * 100 - 10 * 10 = 9900 |
| 11) | 262 * 76 - 62 * 76 = | | 11) ( 262 - 62) * 76 = 15200 |
| 12) | 247 * 45 - 45 * 47 = | | 12) ( 247 - 47) * 45 = 9000 |
| 13) | 270 * 83 - 70 * 83 = | | 13) ( 270 - 70) * 83 = 16600 |
| 14) | 159 * 78 + 78 * 41 = | | 14) ( 159 + 41) * 78 = 15600 |
| 15) | 65 * 33 + 67 * 65 = | | 15) ( 33 + 67) * 65 = 6500 |
| 16) | 53 * 70 + 70 * 47 = | | 16) ( 53 + 47) * 70 = 7000 |
| 17) | 46 * 168 - 46 * 68 = | | 17) ( 168 - 68) * 46 = 4600 |
| 18) | 92 * 171 - 92 * 71 = | | 18) ( 171 - 71) * 92 = 9200 |
| 19) | 51 * 60 + 60 * 49 = | | 19) ( 51 + 49) * 60 = 6000 |
| 20) | 65 * 248 - 48 * 65 = | | 20) ( 248 - 48) * 65 = 13000 |
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Score: ______________ | |
