Math Main Page => Exercises - Math III
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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
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Sunday December 07 2025
08:38:41 PM | Sunday December 07 2025
08:38:41 PMFlip Answers |
| 1) | 310 * 290 = | | 1) 300 * 300 - 10 * 10 = 89900 |
| 2) | 97 * 103 = | | 2) 100 * 100 - 3 * 3 = 9991 |
| 3) | 397 * 403 = | | 3) 400 * 400 - 3 * 3 = 159991 |
| 4) | 201 * 199 = | | 4) 200 * 200 - 1 * 1 = 39999 |
| 5) | 191 * 209 = | | 5) 200 * 200 - 9 * 9 = 39919 |
| 6) | 394 * 406 = | | 6) 400 * 400 - 6 * 6 = 159964 |
| 7) | 190 * 210 = | | 7) 200 * 200 - 10 * 10 = 39900 |
| 8) | 295 * 305 = | | 8) 300 * 300 - 5 * 5 = 89975 |
| 9) | 108 * 92 = | | 9) 100 * 100 - 8 * 8 = 9936 |
| 10) | 305 * 295 = | | 10) 300 * 300 - 5 * 5 = 89975 |
| 11) | 96 * 64 + 96 * 36 = | | 11) ( 64 + 36) * 96 = 9600 |
| 12) | 71 * 23 + 129 * 23 = | | 12) ( 129 + 71) * 23 = 4600 |
| 13) | 66 * 41 + 159 * 66 = | | 13) ( 159 + 41) * 66 = 13200 |
| 14) | 38 * 63 + 38 * 37 = | | 14) ( 37 + 63) * 38 = 3800 |
| 15) | 61 * 29 + 29 * 139 = | | 15) ( 139 + 61) * 29 = 5800 |
| 16) | 254 * 57 - 54 * 57 = | | 16) ( 254 - 54) * 57 = 11400 |
| 17) | 49 * 47 + 49 * 53 = | | 17) ( 53 + 47) * 49 = 4900 |
| 18) | 93 * 257 - 57 * 93 = | | 18) ( 257 - 57) * 93 = 18600 |
| 19) | 78 * 272 - 72 * 78 = | | 19) ( 272 - 72) * 78 = 15600 |
| 20) | 41 * 74 + 41 * 26 = | | 20) ( 26 + 74) * 41 = 4100 |
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Score: ______________ | |
