Find a shortcut to calculate the sum of all numbers from 1 to 99.
1+2+3+4+5+6+.........+95+96+97+98+99
maths question (quick)
2008-01-26 2:09 am
回答 (3)
2008-01-26 2:17 am
✔ 最佳答案
Shortcut:首先,你要把1+2+3+4+5+6+........ .+95+96+97+98+99轉做(1+99)+(2+98)+(3+97).............每個括號都是100,那我們就要把100x49再+50.即4950
2008-01-26 2:21 am
[(1+99)*99]/2
=4950
=4950
收錄日期: 2021-04-13 15:16:37
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