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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Monday August 17 2026
08:17:16 PM | Monday August 17 2026
08:17:16 PMFlip Answers |
| 1) | 408 * 392 = | | 1) 400 * 400 - 8 * 8 = 159936 |
| 2) | 190 * 210 = | | 2) 200 * 200 - 10 * 10 = 39900 |
| 3) | 98 * 102 = | | 3) 100 * 100 - 2 * 2 = 9996 |
| 4) | 310 * 290 = | | 4) 300 * 300 - 10 * 10 = 89900 |
| 5) | 205 * 195 = | | 5) 200 * 200 - 5 * 5 = 39975 |
| 6) | 207 * 193 = | | 6) 200 * 200 - 7 * 7 = 39951 |
| 7) | 295 * 305 = | | 7) 300 * 300 - 5 * 5 = 89975 |
| 8) | 192 * 208 = | | 8) 200 * 200 - 8 * 8 = 39936 |
| 9) | 191 * 209 = | | 9) 200 * 200 - 9 * 9 = 39919 |
| 10) | 299 * 301 = | | 10) 300 * 300 - 1 * 1 = 89999 |
| 11) | 140 * 28 - 40 * 28 = | | 11) ( 140 - 40) * 28 = 2800 |
| 12) | 68 * 138 - 68 * 38 = | | 12) ( 138 - 38) * 68 = 6800 |
| 13) | 68 * 168 - 68 * 68 = | | 13) ( 168 - 68) * 68 = 6800 |
| 14) | 267 * 55 - 67 * 55 = | | 14) ( 267 - 67) * 55 = 11000 |
| 15) | 128 * 88 + 88 * 72 = | | 15) ( 128 + 72) * 88 = 17600 |
| 16) | 162 * 69 + 69 * 38 = | | 16) ( 162 + 38) * 69 = 13800 |
| 17) | 38 * 26 + 62 * 26 = | | 17) ( 62 + 38) * 26 = 2600 |
| 18) | 155 * 21 - 21 * 55 = | | 18) ( 155 - 55) * 21 = 2100 |
| 19) | 65 * 43 + 43 * 135 = | | 19) ( 135 + 65) * 43 = 8600 |
| 20) | 96 * 237 - 37 * 96 = | | 20) ( 237 - 37) * 96 = 19200 |
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Score: ______________ | |
