Click A16.
Click the Insert Function button on the Formula bar.
Type a brief description that describes what you want to do in the Search for a function box.
Then click Go.
If necessary, click a function category you want to use.
Click the function you want to use.
Click OK.
Enter the cell addresses in the text boxes.
Or click the Collapse Dialog button to the right of the text box
Select the cell or range using your mouse.
And then click the Expand Dialog button.
Click OK.