Apple iWork '08 - Manual (Page 86)

86 Chapter 2 Getting Started with Numbers
5 In the Formula Editor or the Formula Bar, select everything inside the left and right
parentheses, and then click cells B7, C7, D7, and E7 to use them as arguments.
6 Click the Accept (green checkmark) button to see the grand total—$40,500.00—
displayed in the bottom-right cell.
Performing Instant Calculations
You can have Numbers perform instant calculations on values in one or more cells.
To use instant calculations:
m Select cells C5 and D5, and view the calculation results in the lower-left corner.
Here are the results of instant
calculations for the two selected cells.