Apple Numbers '08 - Manual (Page 61)

Chapter 3 Using Tables 61
Using the Percentage Format
Use the percentage format to display numeric values followed by the % symbol.
If the value is used in a formula, its decimal number version is used. For example, a
value that displays as 3% is used as 0.03 in a formula.
If you type 3% in a cell formatted using the automatic format and then apply the
percentage format to the cell, the value displayed is 3%. However, if you type 3 in a cell
formatted using the automatic format and then apply the percentage format to the
cell, the value displayed is 300%.
To define a percentage format that displays two decimal places, a thousands separator,
and negative numbers with the negative symbol, select one or more cells and then
click the Percentage Format button in the Format Bar. Use the Decrease Decimal Places
and Increase Decimal Places buttons located nearby to change the number of decimal
places.
For more control over the percentage format, use the Cells Inspector.
To define a percentage format using the Cells Inspector:
1 Select the cell or cells.
2 Click Inspector in the toolbar, and then click the Cells Inspector button.
3 Choose Percentage from the Cell Format pop-up menu.
4 To specify how many decimal places to display, use the Decimals field. If a value
contains more decimal places than you specify, the decimal value displayed is rounded,
not truncated. For example, if a cell is formatted to display two decimal places, the
value 3.456 is displayed as 3.46, not 3.45.
Percentage
Format button
Increase Decimal
Places button
Decrease Decimal
Places button