Math Main Page => Exercises - Math III
|
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
|
|
Friday March 27 2026
07:55:51 PM | Friday March 27 2026
07:55:51 PMFlip Answers |
| 1) | 390 * 410 = | | 1) 400 * 400 - 10 * 10 = 159900 |
| 2) | 406 * 394 = | | 2) 400 * 400 - 6 * 6 = 159964 |
| 3) | 407 * 393 = | | 3) 400 * 400 - 7 * 7 = 159951 |
| 4) | 192 * 208 = | | 4) 200 * 200 - 8 * 8 = 39936 |
| 5) | 103 * 97 = | | 5) 100 * 100 - 3 * 3 = 9991 |
| 6) | 309 * 291 = | | 6) 300 * 300 - 9 * 9 = 89919 |
| 7) | 296 * 304 = | | 7) 300 * 300 - 4 * 4 = 89984 |
| 8) | 106 * 94 = | | 8) 100 * 100 - 6 * 6 = 9964 |
| 9) | 203 * 197 = | | 9) 200 * 200 - 3 * 3 = 39991 |
| 10) | 293 * 307 = | | 10) 300 * 300 - 7 * 7 = 89951 |
| 11) | 175 * 68 - 68 * 75 = | | 11) ( 175 - 75) * 68 = 6800 |
| 12) | 58 * 146 - 46 * 58 = | | 12) ( 146 - 46) * 58 = 5800 |
| 13) | 58 * 91 + 91 * 42 = | | 13) ( 42 + 58) * 91 = 9100 |
| 14) | 147 * 63 + 53 * 63 = | | 14) ( 147 + 53) * 63 = 12600 |
| 15) | 163 * 84 - 84 * 63 = | | 15) ( 163 - 63) * 84 = 8400 |
| 16) | 149 * 91 + 91 * 51 = | | 16) ( 149 + 51) * 91 = 18200 |
| 17) | 39 * 58 + 39 * 42 = | | 17) ( 58 + 42) * 39 = 3900 |
| 18) | 29 * 159 + 29 * 41 = | | 18) ( 159 + 41) * 29 = 5800 |
| 19) | 96 * 129 + 71 * 96 = | | 19) ( 129 + 71) * 96 = 19200 |
| 20) | 65 * 40 + 40 * 35 = | | 20) ( 65 + 35) * 40 = 4000 |
|
Score: ______________ | |
