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 September 21 2026
06:30:17 PM | Monday September 21 2026
06:30:17 PMFlip Answers |
| 1) | 395 * 405 = | | 1) 400 * 400 - 5 * 5 = 159975 |
| 2) | 104 * 96 = | | 2) 100 * 100 - 4 * 4 = 9984 |
| 3) | 104 * 96 = | | 3) 100 * 100 - 4 * 4 = 9984 |
| 4) | 292 * 308 = | | 4) 300 * 300 - 8 * 8 = 89936 |
| 5) | 93 * 107 = | | 5) 100 * 100 - 7 * 7 = 9951 |
| 6) | 93 * 107 = | | 6) 100 * 100 - 7 * 7 = 9951 |
| 7) | 293 * 307 = | | 7) 300 * 300 - 7 * 7 = 89951 |
| 8) | 404 * 396 = | | 8) 400 * 400 - 4 * 4 = 159984 |
| 9) | 210 * 190 = | | 9) 200 * 200 - 10 * 10 = 39900 |
| 10) | 207 * 193 = | | 10) 200 * 200 - 7 * 7 = 39951 |
| 11) | 90 * 44 + 90 * 56 = | | 11) ( 56 + 44) * 90 = 9000 |
| 12) | 64 * 137 - 64 * 37 = | | 12) ( 137 - 37) * 64 = 6400 |
| 13) | 87 * 251 - 51 * 87 = | | 13) ( 251 - 51) * 87 = 17400 |
| 14) | 168 * 88 - 88 * 68 = | | 14) ( 168 - 68) * 88 = 8800 |
| 15) | 82 * 148 - 82 * 48 = | | 15) ( 148 - 48) * 82 = 8200 |
| 16) | 73 * 39 + 61 * 73 = | | 16) ( 39 + 61) * 73 = 7300 |
| 17) | 155 * 41 - 55 * 41 = | | 17) ( 155 - 55) * 41 = 4100 |
| 18) | 22 * 25 + 22 * 75 = | | 18) ( 25 + 75) * 22 = 2200 |
| 19) | 62 * 58 + 138 * 58 = | | 19) ( 138 + 62) * 58 = 11600 |
| 20) | 266 * 54 - 66 * 54 = | | 20) ( 266 - 66) * 54 = 10800 |
|
Score: ______________ | |
