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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Tuesday May 26 2026
11:47:56 PM | Tuesday May 26 2026
11:47:56 PMFlip Answers |
| 1) | 392 * 408 = | | 1) 400 * 400 - 8 * 8 = 159936 |
| 2) | 93 * 107 = | | 2) 100 * 100 - 7 * 7 = 9951 |
| 3) | 399 * 401 = | | 3) 400 * 400 - 1 * 1 = 159999 |
| 4) | 104 * 96 = | | 4) 100 * 100 - 4 * 4 = 9984 |
| 5) | 210 * 190 = | | 5) 200 * 200 - 10 * 10 = 39900 |
| 6) | 390 * 410 = | | 6) 400 * 400 - 10 * 10 = 159900 |
| 7) | 107 * 93 = | | 7) 100 * 100 - 7 * 7 = 9951 |
| 8) | 308 * 292 = | | 8) 300 * 300 - 8 * 8 = 89936 |
| 9) | 110 * 90 = | | 9) 100 * 100 - 10 * 10 = 9900 |
| 10) | 103 * 97 = | | 10) 100 * 100 - 3 * 3 = 9991 |
| 11) | 29 * 73 + 71 * 73 = | | 11) ( 29 + 71) * 73 = 7300 |
| 12) | 80 * 44 + 80 * 56 = | | 12) ( 44 + 56) * 80 = 8000 |
| 13) | 171 * 24 - 71 * 24 = | | 13) ( 171 - 71) * 24 = 2400 |
| 14) | 62 * 51 + 49 * 62 = | | 14) ( 49 + 51) * 62 = 6200 |
| 15) | 22 * 58 + 142 * 22 = | | 15) ( 142 + 58) * 22 = 4400 |
| 16) | 30 * 161 - 30 * 61 = | | 16) ( 161 - 61) * 30 = 3000 |
| 17) | 53 * 171 - 53 * 71 = | | 17) ( 171 - 71) * 53 = 5300 |
| 18) | 54 * 240 - 40 * 54 = | | 18) ( 240 - 40) * 54 = 10800 |
| 19) | 239 * 82 - 82 * 39 = | | 19) ( 239 - 39) * 82 = 16400 |
| 20) | 237 * 91 - 91 * 37 = | | 20) ( 237 - 37) * 91 = 18200 |
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Score: ______________ | |
