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 February 26 2026
04:25:54 PM | Thursday February 26 2026
04:25:54 PMFlip Answers |
| 1) | 397 * 403 = | | 1) 400 * 400 - 3 * 3 = 159991 |
| 2) | 210 * 190 = | | 2) 200 * 200 - 10 * 10 = 39900 |
| 3) | 192 * 208 = | | 3) 200 * 200 - 8 * 8 = 39936 |
| 4) | 408 * 392 = | | 4) 400 * 400 - 8 * 8 = 159936 |
| 5) | 109 * 91 = | | 5) 100 * 100 - 9 * 9 = 9919 |
| 6) | 199 * 201 = | | 6) 200 * 200 - 1 * 1 = 39999 |
| 7) | 394 * 406 = | | 7) 400 * 400 - 6 * 6 = 159964 |
| 8) | 395 * 405 = | | 8) 400 * 400 - 5 * 5 = 159975 |
| 9) | 190 * 210 = | | 9) 200 * 200 - 10 * 10 = 39900 |
| 10) | 196 * 204 = | | 10) 200 * 200 - 4 * 4 = 39984 |
| 11) | 30 * 148 + 30 * 52 = | | 11) ( 148 + 52) * 30 = 6000 |
| 12) | 65 * 258 - 65 * 58 = | | 12) ( 258 - 58) * 65 = 13000 |
| 13) | 48 * 266 - 48 * 66 = | | 13) ( 266 - 66) * 48 = 9600 |
| 14) | 53 * 37 + 37 * 47 = | | 14) ( 53 + 47) * 37 = 3700 |
| 15) | 53 * 249 - 49 * 53 = | | 15) ( 249 - 49) * 53 = 10600 |
| 16) | 42 * 46 + 58 * 46 = | | 16) ( 42 + 58) * 46 = 4600 |
| 17) | 244 * 22 - 22 * 44 = | | 17) ( 244 - 44) * 22 = 4400 |
| 18) | 237 * 40 - 40 * 37 = | | 18) ( 237 - 37) * 40 = 8000 |
| 19) | 78 * 31 + 69 * 78 = | | 19) ( 31 + 69) * 78 = 7800 |
| 20) | 173 * 47 - 47 * 73 = | | 20) ( 173 - 73) * 47 = 4700 |
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Score: ______________ | |
