How to do a SUM on a column

[joshshoestring]

Hi there,
I want to do a SUM of numeral data in a column. How do I do that?

i.e. I have rows of records with repeating IDs which can be grouped by the ID. There's another numeral column which I want to SUM and group according to IDs

 

[joshshoestring]

Ok I'd found it under
Elements > List view settings > Calculations

But how do I just display the SUM without the separate rows? Just group by ID and the SUM