Tip # 20 Calculate running totals

Enter the numbers to be added in column A, say A1 to A5, then enter =SUM($A$1:A1) into column B. Highlight the cells beside the ones with numbers in (in our example, B1 to B5) and go to Edit, Fill, Down. This places the running total of the figures in A1 to A5 in the adjacent column.

Filling Down – the easy way to perform
dynamic calculations.