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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Wednesday September 09 2026
07:55:33 PM | Wednesday September 09 2026
07:55:33 PMFlip Answers |
| 1) | 399 * 401 = | | 1) 400 * 400 - 1 * 1 = 159999 |
| 2) | 306 * 294 = | | 2) 300 * 300 - 6 * 6 = 89964 |
| 3) | 403 * 397 = | | 3) 400 * 400 - 3 * 3 = 159991 |
| 4) | 301 * 299 = | | 4) 300 * 300 - 1 * 1 = 89999 |
| 5) | 309 * 291 = | | 5) 300 * 300 - 9 * 9 = 89919 |
| 6) | 393 * 407 = | | 6) 400 * 400 - 7 * 7 = 159951 |
| 7) | 293 * 307 = | | 7) 300 * 300 - 7 * 7 = 89951 |
| 8) | 304 * 296 = | | 8) 300 * 300 - 4 * 4 = 89984 |
| 9) | 90 * 110 = | | 9) 100 * 100 - 10 * 10 = 9900 |
| 10) | 305 * 295 = | | 10) 300 * 300 - 5 * 5 = 89975 |
| 11) | 157 * 43 - 43 * 57 = | | 11) ( 157 - 57) * 43 = 4300 |
| 12) | 90 * 53 + 47 * 90 = | | 12) ( 47 + 53) * 90 = 9000 |
| 13) | 64 * 86 + 36 * 86 = | | 13) ( 36 + 64) * 86 = 8600 |
| 14) | 48 * 78 + 52 * 78 = | | 14) ( 52 + 48) * 78 = 7800 |
| 15) | 69 * 65 + 69 * 135 = | | 15) ( 135 + 65) * 69 = 13800 |
| 16) | 56 * 55 + 55 * 44 = | | 16) ( 44 + 56) * 55 = 5500 |
| 17) | 68 * 146 + 68 * 54 = | | 17) ( 146 + 54) * 68 = 13600 |
| 18) | 274 * 83 - 74 * 83 = | | 18) ( 274 - 74) * 83 = 16600 |
| 19) | 96 * 168 - 96 * 68 = | | 19) ( 168 - 68) * 96 = 9600 |
| 20) | 73 * 59 + 73 * 41 = | | 20) ( 59 + 41) * 73 = 7300 |
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Score: ______________ | |
