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 06 2026
05:24:45 PM | Friday February 06 2026
05:24:45 PMFlip Answers |
| 1) | 307 * 293 = | | 1) 300 * 300 - 7 * 7 = 89951 |
| 2) | 190 * 210 = | | 2) 200 * 200 - 10 * 10 = 39900 |
| 3) | 203 * 197 = | | 3) 200 * 200 - 3 * 3 = 39991 |
| 4) | 303 * 297 = | | 4) 300 * 300 - 3 * 3 = 89991 |
| 5) | 92 * 108 = | | 5) 100 * 100 - 8 * 8 = 9936 |
| 6) | 391 * 409 = | | 6) 400 * 400 - 9 * 9 = 159919 |
| 7) | 108 * 92 = | | 7) 100 * 100 - 8 * 8 = 9936 |
| 8) | 405 * 395 = | | 8) 400 * 400 - 5 * 5 = 159975 |
| 9) | 94 * 106 = | | 9) 100 * 100 - 6 * 6 = 9964 |
| 10) | 395 * 405 = | | 10) 400 * 400 - 5 * 5 = 159975 |
| 11) | 36 * 265 - 65 * 36 = | | 11) ( 265 - 65) * 36 = 7200 |
| 12) | 257 * 71 - 57 * 71 = | | 12) ( 257 - 57) * 71 = 14200 |
| 13) | 77 * 275 - 75 * 77 = | | 13) ( 275 - 75) * 77 = 15400 |
| 14) | 48 * 88 + 88 * 52 = | | 14) ( 48 + 52) * 88 = 8800 |
| 15) | 67 * 39 + 67 * 61 = | | 15) ( 39 + 61) * 67 = 6700 |
| 16) | 73 * 40 + 60 * 73 = | | 16) ( 40 + 60) * 73 = 7300 |
| 17) | 70 * 31 + 70 * 69 = | | 17) ( 31 + 69) * 70 = 7000 |
| 18) | 142 * 91 - 42 * 91 = | | 18) ( 142 - 42) * 91 = 9100 |
| 19) | 236 * 86 - 36 * 86 = | | 19) ( 236 - 36) * 86 = 17200 |
| 20) | 242 * 91 - 42 * 91 = | | 20) ( 242 - 42) * 91 = 18200 |
|
Score: ______________ | |
