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
12:20:58 PM | Friday April 17 2026
12:20:58 PMFlip Answers |
| 1) | 310 * 290 = | | 1) 300 * 300 - 10 * 10 = 89900 |
| 2) | 108 * 92 = | | 2) 100 * 100 - 8 * 8 = 9936 |
| 3) | 302 * 298 = | | 3) 300 * 300 - 2 * 2 = 89996 |
| 4) | 395 * 405 = | | 4) 400 * 400 - 5 * 5 = 159975 |
| 5) | 305 * 295 = | | 5) 300 * 300 - 5 * 5 = 89975 |
| 6) | 195 * 205 = | | 6) 200 * 200 - 5 * 5 = 39975 |
| 7) | 95 * 105 = | | 7) 100 * 100 - 5 * 5 = 9975 |
| 8) | 207 * 193 = | | 8) 200 * 200 - 7 * 7 = 39951 |
| 9) | 296 * 304 = | | 9) 300 * 300 - 4 * 4 = 89984 |
| 10) | 405 * 395 = | | 10) 400 * 400 - 5 * 5 = 159975 |
| 11) | 86 * 70 + 130 * 86 = | | 11) ( 130 + 70) * 86 = 17200 |
| 12) | 39 * 145 - 39 * 45 = | | 12) ( 145 - 45) * 39 = 3900 |
| 13) | 74 * 24 + 24 * 26 = | | 13) ( 26 + 74) * 24 = 2400 |
| 14) | 238 * 24 - 24 * 38 = | | 14) ( 238 - 38) * 24 = 4800 |
| 15) | 25 * 175 - 75 * 25 = | | 15) ( 175 - 75) * 25 = 2500 |
| 16) | 59 * 260 - 59 * 60 = | | 16) ( 260 - 60) * 59 = 11800 |
| 17) | 77 * 61 + 39 * 77 = | | 17) ( 39 + 61) * 77 = 7700 |
| 18) | 25 * 249 - 49 * 25 = | | 18) ( 249 - 49) * 25 = 5000 |
| 19) | 47 * 77 + 77 * 153 = | | 19) ( 153 + 47) * 77 = 15400 |
| 20) | 253 * 79 - 53 * 79 = | | 20) ( 253 - 53) * 79 = 15800 |
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Score: ______________ | |
