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 November 06 2026
12:55:25 PM | Friday November 06 2026
12:55:25 PMFlip Answers |
| 1) | 203 * 197 = | | 1) 200 * 200 - 3 * 3 = 39991 |
| 2) | 299 * 301 = | | 2) 300 * 300 - 1 * 1 = 89999 |
| 3) | 410 * 390 = | | 3) 400 * 400 - 10 * 10 = 159900 |
| 4) | 210 * 190 = | | 4) 200 * 200 - 10 * 10 = 39900 |
| 5) | 97 * 103 = | | 5) 100 * 100 - 3 * 3 = 9991 |
| 6) | 94 * 106 = | | 6) 100 * 100 - 6 * 6 = 9964 |
| 7) | 394 * 406 = | | 7) 400 * 400 - 6 * 6 = 159964 |
| 8) | 202 * 198 = | | 8) 200 * 200 - 2 * 2 = 39996 |
| 9) | 94 * 106 = | | 9) 100 * 100 - 6 * 6 = 9964 |
| 10) | 198 * 202 = | | 10) 200 * 200 - 2 * 2 = 39996 |
| 11) | 39 * 139 - 39 * 39 = | | 11) ( 139 - 39) * 39 = 3900 |
| 12) | 49 * 67 + 133 * 49 = | | 12) ( 133 + 67) * 49 = 9800 |
| 13) | 151 * 92 - 92 * 51 = | | 13) ( 151 - 51) * 92 = 9200 |
| 14) | 251 * 31 - 31 * 51 = | | 14) ( 251 - 51) * 31 = 6200 |
| 15) | 21 * 262 - 21 * 62 = | | 15) ( 262 - 62) * 21 = 4200 |
| 16) | 22 * 71 + 22 * 129 = | | 16) ( 129 + 71) * 22 = 4400 |
| 17) | 163 * 53 - 63 * 53 = | | 17) ( 163 - 63) * 53 = 5300 |
| 18) | 235 * 92 - 35 * 92 = | | 18) ( 235 - 35) * 92 = 18400 |
| 19) | 70 * 42 + 42 * 30 = | | 19) ( 30 + 70) * 42 = 4200 |
| 20) | 251 * 77 - 51 * 77 = | | 20) ( 251 - 51) * 77 = 15400 |
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Score: ______________ | |
