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 July 06 2026
12:37:48 AM | Monday July 06 2026
12:37:48 AMFlip Answers |
| 1) | 409 * 391 = | | 1) 400 * 400 - 9 * 9 = 159919 |
| 2) | 396 * 404 = | | 2) 400 * 400 - 4 * 4 = 159984 |
| 3) | 199 * 201 = | | 3) 200 * 200 - 1 * 1 = 39999 |
| 4) | 206 * 194 = | | 4) 200 * 200 - 6 * 6 = 39964 |
| 5) | 98 * 102 = | | 5) 100 * 100 - 2 * 2 = 9996 |
| 6) | 204 * 196 = | | 6) 200 * 200 - 4 * 4 = 39984 |
| 7) | 210 * 190 = | | 7) 200 * 200 - 10 * 10 = 39900 |
| 8) | 294 * 306 = | | 8) 300 * 300 - 6 * 6 = 89964 |
| 9) | 191 * 209 = | | 9) 200 * 200 - 9 * 9 = 39919 |
| 10) | 206 * 194 = | | 10) 200 * 200 - 6 * 6 = 39964 |
| 11) | 93 * 47 + 93 * 53 = | | 11) ( 47 + 53) * 93 = 9300 |
| 12) | 241 * 65 - 41 * 65 = | | 12) ( 241 - 41) * 65 = 13000 |
| 13) | 37 * 34 + 163 * 34 = | | 13) ( 163 + 37) * 34 = 6800 |
| 14) | 50 * 39 + 50 * 61 = | | 14) ( 61 + 39) * 50 = 5000 |
| 15) | 53 * 55 + 45 * 53 = | | 15) ( 55 + 45) * 53 = 5300 |
| 16) | 270 * 48 - 48 * 70 = | | 16) ( 270 - 70) * 48 = 9600 |
| 17) | 42 * 273 - 42 * 73 = | | 17) ( 273 - 73) * 42 = 8400 |
| 18) | 160 * 34 - 34 * 60 = | | 18) ( 160 - 60) * 34 = 3400 |
| 19) | 72 * 239 - 72 * 39 = | | 19) ( 239 - 39) * 72 = 14400 |
| 20) | 71 * 31 + 31 * 29 = | | 20) ( 29 + 71) * 31 = 3100 |
|
Score: ______________ | |
