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 November 21 2025
07:26:46 PM | Friday November 21 2025
07:26:46 PMFlip Answers |
| 1) | 105 * 95 = | | 1) 100 * 100 - 5 * 5 = 9975 |
| 2) | 393 * 407 = | | 2) 400 * 400 - 7 * 7 = 159951 |
| 3) | 406 * 394 = | | 3) 400 * 400 - 6 * 6 = 159964 |
| 4) | 210 * 190 = | | 4) 200 * 200 - 10 * 10 = 39900 |
| 5) | 398 * 402 = | | 5) 400 * 400 - 2 * 2 = 159996 |
| 6) | 99 * 101 = | | 6) 100 * 100 - 1 * 1 = 9999 |
| 7) | 93 * 107 = | | 7) 100 * 100 - 7 * 7 = 9951 |
| 8) | 198 * 202 = | | 8) 200 * 200 - 2 * 2 = 39996 |
| 9) | 206 * 194 = | | 9) 200 * 200 - 6 * 6 = 39964 |
| 10) | 98 * 102 = | | 10) 100 * 100 - 2 * 2 = 9996 |
| 11) | 86 * 159 + 41 * 86 = | | 11) ( 159 + 41) * 86 = 17200 |
| 12) | 87 * 40 + 160 * 87 = | | 12) ( 160 + 40) * 87 = 17400 |
| 13) | 32 * 257 - 32 * 57 = | | 13) ( 257 - 57) * 32 = 6400 |
| 14) | 61 * 156 - 61 * 56 = | | 14) ( 156 - 56) * 61 = 6100 |
| 15) | 160 * 24 - 60 * 24 = | | 15) ( 160 - 60) * 24 = 2400 |
| 16) | 34 * 32 + 32 * 66 = | | 16) ( 34 + 66) * 32 = 3200 |
| 17) | 34 * 175 - 75 * 34 = | | 17) ( 175 - 75) * 34 = 3400 |
| 18) | 158 * 97 - 58 * 97 = | | 18) ( 158 - 58) * 97 = 9700 |
| 19) | 25 * 45 + 55 * 25 = | | 19) ( 45 + 55) * 25 = 2500 |
| 20) | 66 * 260 - 60 * 66 = | | 20) ( 260 - 60) * 66 = 13200 |
|
Score: ______________ | |
