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 August 08 2026
12:47:13 PM | Saturday August 08 2026
12:47:13 PMFlip Answers |
| 1) | 291 * 309 = | | 1) 300 * 300 - 9 * 9 = 89919 |
| 2) | 108 * 92 = | | 2) 100 * 100 - 8 * 8 = 9936 |
| 3) | 110 * 90 = | | 3) 100 * 100 - 10 * 10 = 9900 |
| 4) | 96 * 104 = | | 4) 100 * 100 - 4 * 4 = 9984 |
| 5) | 392 * 408 = | | 5) 400 * 400 - 8 * 8 = 159936 |
| 6) | 194 * 206 = | | 6) 200 * 200 - 6 * 6 = 39964 |
| 7) | 293 * 307 = | | 7) 300 * 300 - 7 * 7 = 89951 |
| 8) | 391 * 409 = | | 8) 400 * 400 - 9 * 9 = 159919 |
| 9) | 401 * 399 = | | 9) 400 * 400 - 1 * 1 = 159999 |
| 10) | 207 * 193 = | | 10) 200 * 200 - 7 * 7 = 39951 |
| 11) | 60 * 94 + 40 * 94 = | | 11) ( 60 + 40) * 94 = 9400 |
| 12) | 152 * 46 - 46 * 52 = | | 12) ( 152 - 52) * 46 = 4600 |
| 13) | 145 * 68 - 68 * 45 = | | 13) ( 145 - 45) * 68 = 6800 |
| 14) | 53 * 23 + 23 * 47 = | | 14) ( 47 + 53) * 23 = 2300 |
| 15) | 31 * 255 - 55 * 31 = | | 15) ( 255 - 55) * 31 = 6200 |
| 16) | 72 * 30 + 128 * 30 = | | 16) ( 128 + 72) * 30 = 6000 |
| 17) | 70 * 27 + 27 * 30 = | | 17) ( 30 + 70) * 27 = 2700 |
| 18) | 162 * 78 + 78 * 38 = | | 18) ( 162 + 38) * 78 = 15600 |
| 19) | 58 * 41 + 41 * 42 = | | 19) ( 42 + 58) * 41 = 4100 |
| 20) | 63 * 69 + 137 * 69 = | | 20) ( 137 + 63) * 69 = 13800 |
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Score: ______________ | |
