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
|
|
Thursday April 23 2026
02:04:02 PM | Thursday April 23 2026
02:04:02 PMFlip Answers |
| 1) | 397 * 403 = | | 1) 400 * 400 - 3 * 3 = 159991 |
| 2) | 196 * 204 = | | 2) 200 * 200 - 4 * 4 = 39984 |
| 3) | 394 * 406 = | | 3) 400 * 400 - 6 * 6 = 159964 |
| 4) | 406 * 394 = | | 4) 400 * 400 - 6 * 6 = 159964 |
| 5) | 405 * 395 = | | 5) 400 * 400 - 5 * 5 = 159975 |
| 6) | 305 * 295 = | | 6) 300 * 300 - 5 * 5 = 89975 |
| 7) | 410 * 390 = | | 7) 400 * 400 - 10 * 10 = 159900 |
| 8) | 199 * 201 = | | 8) 200 * 200 - 1 * 1 = 39999 |
| 9) | 308 * 292 = | | 9) 300 * 300 - 8 * 8 = 89936 |
| 10) | 192 * 208 = | | 10) 200 * 200 - 8 * 8 = 39936 |
| 11) | 51 * 38 + 149 * 38 = | | 11) ( 149 + 51) * 38 = 7600 |
| 12) | 78 * 275 - 78 * 75 = | | 12) ( 275 - 75) * 78 = 15600 |
| 13) | 140 * 33 - 40 * 33 = | | 13) ( 140 - 40) * 33 = 3300 |
| 14) | 66 * 25 + 134 * 25 = | | 14) ( 134 + 66) * 25 = 5000 |
| 15) | 84 * 271 - 84 * 71 = | | 15) ( 271 - 71) * 84 = 16800 |
| 16) | 83 * 155 + 83 * 45 = | | 16) ( 155 + 45) * 83 = 16600 |
| 17) | 237 * 31 - 31 * 37 = | | 17) ( 237 - 37) * 31 = 6200 |
| 18) | 175 * 28 - 75 * 28 = | | 18) ( 175 - 75) * 28 = 2800 |
| 19) | 165 * 85 - 65 * 85 = | | 19) ( 165 - 65) * 85 = 8500 |
| 20) | 35 * 170 - 35 * 70 = | | 20) ( 170 - 70) * 35 = 3500 |
|
Score: ______________ | |
