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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Saturday March 14 2026
02:05:49 PM | Saturday March 14 2026
02:05:49 PMFlip Answers |
| 1) | 399 * 401 = | | 1) 400 * 400 - 1 * 1 = 159999 |
| 2) | 104 * 96 = | | 2) 100 * 100 - 4 * 4 = 9984 |
| 3) | 398 * 402 = | | 3) 400 * 400 - 2 * 2 = 159996 |
| 4) | 297 * 303 = | | 4) 300 * 300 - 3 * 3 = 89991 |
| 5) | 197 * 203 = | | 5) 200 * 200 - 3 * 3 = 39991 |
| 6) | 391 * 409 = | | 6) 400 * 400 - 9 * 9 = 159919 |
| 7) | 398 * 402 = | | 7) 400 * 400 - 2 * 2 = 159996 |
| 8) | 393 * 407 = | | 8) 400 * 400 - 7 * 7 = 159951 |
| 9) | 309 * 291 = | | 9) 300 * 300 - 9 * 9 = 89919 |
| 10) | 409 * 391 = | | 10) 400 * 400 - 9 * 9 = 159919 |
| 11) | 92 * 58 + 42 * 92 = | | 11) ( 58 + 42) * 92 = 9200 |
| 12) | 29 * 60 + 29 * 140 = | | 12) ( 140 + 60) * 29 = 5800 |
| 13) | 162 * 36 - 36 * 62 = | | 13) ( 162 - 62) * 36 = 3600 |
| 14) | 38 * 36 + 38 * 64 = | | 14) ( 64 + 36) * 38 = 3800 |
| 15) | 130 * 38 + 70 * 38 = | | 15) ( 130 + 70) * 38 = 7600 |
| 16) | 152 * 54 - 52 * 54 = | | 16) ( 152 - 52) * 54 = 5400 |
| 17) | 66 * 93 + 34 * 93 = | | 17) ( 34 + 66) * 93 = 9300 |
| 18) | 76 * 131 + 76 * 69 = | | 18) ( 131 + 69) * 76 = 15200 |
| 19) | 59 * 89 + 41 * 89 = | | 19) ( 41 + 59) * 89 = 8900 |
| 20) | 150 * 58 - 50 * 58 = | | 20) ( 150 - 50) * 58 = 5800 |
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Score: ______________ | |
