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
|
|
Monday January 26 2026
03:02:52 PM | Monday January 26 2026
03:02:52 PMFlip Answers |
| 1) | 401 * 399 = | | 1) 400 * 400 - 1 * 1 = 159999 |
| 2) | 108 * 92 = | | 2) 100 * 100 - 8 * 8 = 9936 |
| 3) | 110 * 90 = | | 3) 100 * 100 - 10 * 10 = 9900 |
| 4) | 397 * 403 = | | 4) 400 * 400 - 3 * 3 = 159991 |
| 5) | 98 * 102 = | | 5) 100 * 100 - 2 * 2 = 9996 |
| 6) | 204 * 196 = | | 6) 200 * 200 - 4 * 4 = 39984 |
| 7) | 399 * 401 = | | 7) 400 * 400 - 1 * 1 = 159999 |
| 8) | 392 * 408 = | | 8) 400 * 400 - 8 * 8 = 159936 |
| 9) | 399 * 401 = | | 9) 400 * 400 - 1 * 1 = 159999 |
| 10) | 407 * 393 = | | 10) 400 * 400 - 7 * 7 = 159951 |
| 11) | 95 * 47 + 153 * 95 = | | 11) ( 153 + 47) * 95 = 19000 |
| 12) | 82 * 65 + 35 * 82 = | | 12) ( 35 + 65) * 82 = 8200 |
| 13) | 80 * 75 + 80 * 25 = | | 13) ( 25 + 75) * 80 = 8000 |
| 14) | 57 * 46 + 57 * 54 = | | 14) ( 46 + 54) * 57 = 5700 |
| 15) | 47 * 267 - 47 * 67 = | | 15) ( 267 - 67) * 47 = 9400 |
| 16) | 135 * 90 + 90 * 65 = | | 16) ( 135 + 65) * 90 = 18000 |
| 17) | 241 * 68 - 41 * 68 = | | 17) ( 241 - 41) * 68 = 13600 |
| 18) | 40 * 42 + 58 * 40 = | | 18) ( 42 + 58) * 40 = 4000 |
| 19) | 126 * 94 + 74 * 94 = | | 19) ( 126 + 74) * 94 = 18800 |
| 20) | 79 * 145 - 79 * 45 = | | 20) ( 145 - 45) * 79 = 7900 |
|
Score: ______________ | |
