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 February 13 2026
01:39:31 PM | Friday February 13 2026
01:39:31 PMFlip Answers |
| 1) | 209 * 191 = | | 1) 200 * 200 - 9 * 9 = 39919 |
| 2) | 105 * 95 = | | 2) 100 * 100 - 5 * 5 = 9975 |
| 3) | 191 * 209 = | | 3) 200 * 200 - 9 * 9 = 39919 |
| 4) | 107 * 93 = | | 4) 100 * 100 - 7 * 7 = 9951 |
| 5) | 310 * 290 = | | 5) 300 * 300 - 10 * 10 = 89900 |
| 6) | 191 * 209 = | | 6) 200 * 200 - 9 * 9 = 39919 |
| 7) | 92 * 108 = | | 7) 100 * 100 - 8 * 8 = 9936 |
| 8) | 298 * 302 = | | 8) 300 * 300 - 2 * 2 = 89996 |
| 9) | 208 * 192 = | | 9) 200 * 200 - 8 * 8 = 39936 |
| 10) | 394 * 406 = | | 10) 400 * 400 - 6 * 6 = 159964 |
| 11) | 163 * 94 - 63 * 94 = | | 11) ( 163 - 63) * 94 = 9400 |
| 12) | 265 * 93 - 93 * 65 = | | 12) ( 265 - 65) * 93 = 18600 |
| 13) | 55 * 148 - 48 * 55 = | | 13) ( 148 - 48) * 55 = 5500 |
| 14) | 142 * 33 - 42 * 33 = | | 14) ( 142 - 42) * 33 = 3300 |
| 15) | 146 * 26 + 26 * 54 = | | 15) ( 146 + 54) * 26 = 5200 |
| 16) | 26 * 144 - 26 * 44 = | | 16) ( 144 - 44) * 26 = 2600 |
| 17) | 38 * 153 - 38 * 53 = | | 17) ( 153 - 53) * 38 = 3800 |
| 18) | 78 * 74 + 26 * 78 = | | 18) ( 26 + 74) * 78 = 7800 |
| 19) | 59 * 270 - 70 * 59 = | | 19) ( 270 - 70) * 59 = 11800 |
| 20) | 38 * 66 + 162 * 66 = | | 20) ( 162 + 38) * 66 = 13200 |
|
Score: ______________ | |
