maths question (quick)

🎓 學業台小學及中學教育

用戶161263

2008-01-26 2:09 am

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

回答 (3)

用戶105108

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

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Wai Yin

2008-01-26 2:38 am

[(1+99)*99]/2
=4950

參考: my

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Venus

2008-01-26 2:21 am

[(1+99)*99]/2
=4950

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