Whats this meant to be… its not valid as far as I can see. Guessing your missing * or /
Similar with your total line I would imagine. dont think you can tack .sum on the end of a calculation like that.
Make sure you highlight and click < / > button on forum post editor to show its code and prevent any html stripping etc.
If you already have you * then I would ask why the ( ) brackets? Where have you seen that?