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 February 20 2026
01:46:09 AM | Friday February 20 2026
01:46:09 AMFlip Answers |
| 1) | 401 * 399 = | | 1) 400 * 400 - 1 * 1 = 159999 |
| 2) | 405 * 395 = | | 2) 400 * 400 - 5 * 5 = 159975 |
| 3) | 207 * 193 = | | 3) 200 * 200 - 7 * 7 = 39951 |
| 4) | 204 * 196 = | | 4) 200 * 200 - 4 * 4 = 39984 |
| 5) | 304 * 296 = | | 5) 300 * 300 - 4 * 4 = 89984 |
| 6) | 91 * 109 = | | 6) 100 * 100 - 9 * 9 = 9919 |
| 7) | 299 * 301 = | | 7) 300 * 300 - 1 * 1 = 89999 |
| 8) | 198 * 202 = | | 8) 200 * 200 - 2 * 2 = 39996 |
| 9) | 199 * 201 = | | 9) 200 * 200 - 1 * 1 = 39999 |
| 10) | 109 * 91 = | | 10) 100 * 100 - 9 * 9 = 9919 |
| 11) | 66 * 82 + 82 * 134 = | | 11) ( 134 + 66) * 82 = 16400 |
| 12) | 40 * 23 + 60 * 23 = | | 12) ( 60 + 40) * 23 = 2300 |
| 13) | 48 * 42 + 42 * 52 = | | 13) ( 52 + 48) * 42 = 4200 |
| 14) | 78 * 71 + 78 * 29 = | | 14) ( 29 + 71) * 78 = 7800 |
| 15) | 62 * 77 + 77 * 38 = | | 15) ( 38 + 62) * 77 = 7700 |
| 16) | 34 * 89 + 66 * 89 = | | 16) ( 34 + 66) * 89 = 8900 |
| 17) | 166 * 23 - 66 * 23 = | | 17) ( 166 - 66) * 23 = 2300 |
| 18) | 89 * 248 - 48 * 89 = | | 18) ( 248 - 48) * 89 = 17800 |
| 19) | 128 * 81 + 81 * 72 = | | 19) ( 128 + 72) * 81 = 16200 |
| 20) | 145 * 66 - 45 * 66 = | | 20) ( 145 - 45) * 66 = 6600 |
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Score: ______________ | |
