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 :)

In reply to Re^2: Finding sum of all digits from 1 to 1 million. by Anonymous Monk
in thread Finding sum of all digits from 1 to 1 million. by vladb

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