The bottom-left corner of every Numbers document includes buttons for sum, avg, min, max, and count functions. With no cells selected, no information is displayed next to the buttons. However, if you select two or more cells, Numbers instantly fills in, respectively, the:
These buttons not only provide a handy way to get quick calculations, but Numbers also lets you use them to quickly add a function to your table. Let’s say, for example, that you’d like to total the first column in a table.
To add the Sum function to a column:
Numbers adds the function to the cell and even picks up the formatting of the selected cells. You can add a Sum function to a row of cells just as easily.
To add a Sum function to a row of cells:
Whether you add the function to your table or simply select a series of cells to perform calculations on the fly, this little trick can be very helpful.