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 September 17 2026
09:27:37 AM | Thursday September 17 2026
09:27:37 AMFlip Answers |
| 1) | 204 * 196 = | | 1) 200 * 200 - 4 * 4 = 39984 |
| 2) | 91 * 109 = | | 2) 100 * 100 - 9 * 9 = 9919 |
| 3) | 290 * 310 = | | 3) 300 * 300 - 10 * 10 = 89900 |
| 4) | 392 * 408 = | | 4) 400 * 400 - 8 * 8 = 159936 |
| 5) | 402 * 398 = | | 5) 400 * 400 - 2 * 2 = 159996 |
| 6) | 409 * 391 = | | 6) 400 * 400 - 9 * 9 = 159919 |
| 7) | 301 * 299 = | | 7) 300 * 300 - 1 * 1 = 89999 |
| 8) | 93 * 107 = | | 8) 100 * 100 - 7 * 7 = 9951 |
| 9) | 409 * 391 = | | 9) 400 * 400 - 9 * 9 = 159919 |
| 10) | 201 * 199 = | | 10) 200 * 200 - 1 * 1 = 39999 |
| 11) | 68 * 30 + 70 * 68 = | | 11) ( 30 + 70) * 68 = 6800 |
| 12) | 41 * 69 + 159 * 69 = | | 12) ( 159 + 41) * 69 = 13800 |
| 13) | 51 * 86 + 49 * 86 = | | 13) ( 49 + 51) * 86 = 8600 |
| 14) | 68 * 39 + 68 * 161 = | | 14) ( 161 + 39) * 68 = 13600 |
| 15) | 86 * 45 + 55 * 86 = | | 15) ( 55 + 45) * 86 = 8600 |
| 16) | 68 * 60 + 60 * 132 = | | 16) ( 132 + 68) * 60 = 12000 |
| 17) | 40 * 42 + 40 * 158 = | | 17) ( 158 + 42) * 40 = 8000 |
| 18) | 237 * 90 - 90 * 37 = | | 18) ( 237 - 37) * 90 = 18000 |
| 19) | 74 * 29 + 71 * 74 = | | 19) ( 29 + 71) * 74 = 7400 |
| 20) | 33 * 60 + 33 * 40 = | | 20) ( 60 + 40) * 33 = 3300 |
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Score: ______________ | |
