You can use spreadsheets to distil a few important pieces of information out of several pages of data. For example, say you want to hunt through a column looking for minimums and maximums, in order to find the lowest-priced product or best sales quarter. Or maybe you want to calculate averages, means, and percentile rankings to help grade a class of students. In either case, Excel provides a number of useful functions. Most of these are part of the Statistical group, although the SUM() function is actually part of the Math & Trig group.
Almost every Excel program in existence has been called on at least once to do the same thing: add a group of numbers. This task falls to the wildly popular SUM() function, which simply adds everything in it. The SUM() function takes over 200 arguments, each of which can be a single cell reference or a range of cells.
Here's a SUM() formula that adds two cells:
And here's a SUM() formula that adds the range of 11 cells from A2 to A12:
And here's a SUM() formula that adds a range of cells along with a separately referenced cell, and two literal values:
The SUM() function automatically ignores any cells in its range with text content, or any blank ones. However, SUM() adds up calendar dates (which are actually specially formatted numbers, as you saw on Regional Dating). Therefore, make sure you don't sum a range of cells that includes a date.