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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Thursday April 16 2026
04:04:28 PM | Thursday April 16 2026
04:04:28 PMFlip Answers |
| 1) | 291 * 309 = | | 1) 300 * 300 - 9 * 9 = 89919 |
| 2) | 194 * 206 = | | 2) 200 * 200 - 6 * 6 = 39964 |
| 3) | 292 * 308 = | | 3) 300 * 300 - 8 * 8 = 89936 |
| 4) | 310 * 290 = | | 4) 300 * 300 - 10 * 10 = 89900 |
| 5) | 198 * 202 = | | 5) 200 * 200 - 2 * 2 = 39996 |
| 6) | 392 * 408 = | | 6) 400 * 400 - 8 * 8 = 159936 |
| 7) | 398 * 402 = | | 7) 400 * 400 - 2 * 2 = 159996 |
| 8) | 392 * 408 = | | 8) 400 * 400 - 8 * 8 = 159936 |
| 9) | 103 * 97 = | | 9) 100 * 100 - 3 * 3 = 9991 |
| 10) | 204 * 196 = | | 10) 200 * 200 - 4 * 4 = 39984 |
| 11) | 57 * 72 + 43 * 72 = | | 11) ( 43 + 57) * 72 = 7200 |
| 12) | 40 * 170 - 40 * 70 = | | 12) ( 170 - 70) * 40 = 4000 |
| 13) | 60 * 51 + 60 * 49 = | | 13) ( 49 + 51) * 60 = 6000 |
| 14) | 140 * 70 + 60 * 70 = | | 14) ( 140 + 60) * 70 = 14000 |
| 15) | 238 * 63 - 38 * 63 = | | 15) ( 238 - 38) * 63 = 12600 |
| 16) | 34 * 251 - 51 * 34 = | | 16) ( 251 - 51) * 34 = 6800 |
| 17) | 94 * 171 - 94 * 71 = | | 17) ( 171 - 71) * 94 = 9400 |
| 18) | 148 * 90 - 48 * 90 = | | 18) ( 148 - 48) * 90 = 9000 |
| 19) | 39 * 24 + 61 * 24 = | | 19) ( 61 + 39) * 24 = 2400 |
| 20) | 68 * 154 + 68 * 46 = | | 20) ( 154 + 46) * 68 = 13600 |
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Score: ______________ | |
