Apple iWork '08 - Manual (Page 80)

80 Chapter 2 Getting Started with Numbers
Step 4: Use Formulas and Functions
Numbers can automatically perform calculations for you. For example, you can have
a spreadsheet automatically add a column of numbers and display the sum in a
table cell.
To display the results of a calculation in a table cell, you add a formula to that cell. Most
formula calculations are done using values in other table cells.
Formulas use the following:
 Operators perform operations such as addition (+). For example, =A2 + 16 is a formula
that adds 16 to the value in cell A2. When the value in A2 changes, so does the value
in the cell containing the formula.
Note: All formulas must begin with an equal sign (=). For simplicity, the equal sign
may be omitted in explanatory text.
 Functions are predefined, named operations, such as SUM and AVERAGE. To use a
function, you select it from a list or type its name, and then specify the arguments
the function needs in parentheses following the function’s name.
 Arguments provide the data that a function uses to perform its operations.
For example, SUM(A2, 16, B4) adds three values. Notice that arguments are separated
using commas.
Numbers provides several tools for working with formulas. In the following pages,
you’ll practice using all of them.