Apple Numbers '09 - Manual (Page 92)

This content in a cell assigned the
automatic format Is formatted like this for display
A duration value A number accompanied by a duration suffix
(w or weeks, d or days, h or hours, m or minutes,
s or seconds, ms or milliseconds) is treated as a
duration value in formulas. The suffix is displayed
in its abbreviated form.
For example, 2 weeks is displayed as 2w.
A fraction value The value is formatted like a date if it matches
one of the formats available for date values.
Otherwise, the “Up to three digits” accuracy is
used for display.
For example, 1/1 displays as Jan 1, 2008.
If a different format has been applied to a cell, you can change its format to automatic
by selecting the cell and choosing Automatic from the Cell Formats pop-up menu in
the format bar.
You can also use the Cells inspector.
To apply the automatic 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 Automatic from the Cell Format pop-up menu.
Using the Number Format in Table Cells
Use the number format to format the display of a number’s decimal places, thousands
separator, and negative values.
92 Chapter 4 Working with Table Cells