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
|
|
Wednesday January 07 2026
12:20:57 AM | Wednesday January 07 2026
12:20:57 AMFlip Answers |
| 1) | 391 * 409 = | | 1) 400 * 400 - 9 * 9 = 159919 |
| 2) | 93 * 107 = | | 2) 100 * 100 - 7 * 7 = 9951 |
| 3) | 199 * 201 = | | 3) 200 * 200 - 1 * 1 = 39999 |
| 4) | 204 * 196 = | | 4) 200 * 200 - 4 * 4 = 39984 |
| 5) | 197 * 203 = | | 5) 200 * 200 - 3 * 3 = 39991 |
| 6) | 98 * 102 = | | 6) 100 * 100 - 2 * 2 = 9996 |
| 7) | 91 * 109 = | | 7) 100 * 100 - 9 * 9 = 9919 |
| 8) | 95 * 105 = | | 8) 100 * 100 - 5 * 5 = 9975 |
| 9) | 297 * 303 = | | 9) 300 * 300 - 3 * 3 = 89991 |
| 10) | 202 * 198 = | | 10) 200 * 200 - 2 * 2 = 39996 |
| 11) | 72 * 74 + 126 * 72 = | | 11) ( 126 + 74) * 72 = 14400 |
| 12) | 160 * 29 - 29 * 60 = | | 12) ( 160 - 60) * 29 = 2900 |
| 13) | 239 * 54 - 54 * 39 = | | 13) ( 239 - 39) * 54 = 10800 |
| 14) | 65 * 79 + 79 * 135 = | | 14) ( 135 + 65) * 79 = 15800 |
| 15) | 24 * 235 - 24 * 35 = | | 15) ( 235 - 35) * 24 = 4800 |
| 16) | 275 * 65 - 75 * 65 = | | 16) ( 275 - 75) * 65 = 13000 |
| 17) | 75 * 135 + 75 * 65 = | | 17) ( 135 + 65) * 75 = 15000 |
| 18) | 60 * 135 - 35 * 60 = | | 18) ( 135 - 35) * 60 = 6000 |
| 19) | 29 * 75 + 75 * 71 = | | 19) ( 29 + 71) * 75 = 7500 |
| 20) | 39 * 61 + 61 * 61 = | | 20) ( 61 + 39) * 61 = 6100 |
|
Score: ______________ | |
