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Re: Finding sum of all digits from 1 to 1 million.

by vagnerr (Prior)
 on Jan 24, 2002 at 00:17 UTC ( #141011=note: print w/replies, xml ) Need Help??

I think you may be right. I don't think the answer you have is correct. There is actualy a formula to calculate the sum of the numbers from 1-n. It is (n^2)/2 + n/2 which in the case of n=1000000 the answer is 500000500000

---If it doesn't fit use a bigger hammer
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Re^2: Finding sum of all digits from 1 to 1 million.
by Anonymous Monk on Jan 30, 2013 at 08:59 UTC
The formula you need is:- 1/2n (n+1) N is the number. Eg (all numbers from one to ten), ten is number. So 1/2 * 10 =5 * (10+1) =55 Comes from sigma notation.....and i never got any gcses :)

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