As Gauss found out when in elementary school" SUM(1,2, .....N) = N*(N+1)/2
So with N in A1 use = A1*(A1+1)/2

Homework?
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Bernard V Liengme
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"LAdekoya" wrote in message
...
I am looking for a formula to which I can supply a number N and have it
calculate 1+2+3+4.....+N. I realise that I can enter 1 to N in as many
cells
then use SUM but this won't do for what I need to achieve.