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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Friday April 17 2026
06:24:43 PM | Friday April 17 2026
06:24:43 PMFlip Answers |
| 1) | 403 * 397 = | | 1) 400 * 400 - 3 * 3 = 159991 |
| 2) | 395 * 405 = | | 2) 400 * 400 - 5 * 5 = 159975 |
| 3) | 406 * 394 = | | 3) 400 * 400 - 6 * 6 = 159964 |
| 4) | 190 * 210 = | | 4) 200 * 200 - 10 * 10 = 39900 |
| 5) | 292 * 308 = | | 5) 300 * 300 - 8 * 8 = 89936 |
| 6) | 199 * 201 = | | 6) 200 * 200 - 1 * 1 = 39999 |
| 7) | 109 * 91 = | | 7) 100 * 100 - 9 * 9 = 9919 |
| 8) | 407 * 393 = | | 8) 400 * 400 - 7 * 7 = 159951 |
| 9) | 403 * 397 = | | 9) 400 * 400 - 3 * 3 = 159991 |
| 10) | 201 * 199 = | | 10) 200 * 200 - 1 * 1 = 39999 |
| 11) | 130 * 32 + 70 * 32 = | | 11) ( 130 + 70) * 32 = 6400 |
| 12) | 157 * 58 - 57 * 58 = | | 12) ( 157 - 57) * 58 = 5800 |
| 13) | 65 * 65 + 35 * 65 = | | 13) ( 35 + 65) * 65 = 6500 |
| 14) | 68 * 79 + 79 * 32 = | | 14) ( 32 + 68) * 79 = 7900 |
| 15) | 67 * 33 + 33 * 33 = | | 15) ( 33 + 67) * 33 = 3300 |
| 16) | 243 * 51 - 43 * 51 = | | 16) ( 243 - 43) * 51 = 10200 |
| 17) | 70 * 40 + 70 * 60 = | | 17) ( 40 + 60) * 70 = 7000 |
| 18) | 46 * 53 + 53 * 154 = | | 18) ( 154 + 46) * 53 = 10600 |
| 19) | 137 * 21 - 21 * 37 = | | 19) ( 137 - 37) * 21 = 2100 |
| 20) | 37 * 258 - 37 * 58 = | | 20) ( 258 - 58) * 37 = 7400 |
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Score: ______________ | |
