Appendix 2: Using Custom Number Formats
Although Excel provides a good variety of built-in number formats, you may find that none of these suits your needs. This appendix describes how to create custom number formats and provides many examples.
About Number Formatting
By default, all cells use the General number format. This is basically a “what you type is what you get” format. If the cell is not wide enough to show the entire number, the General format rounds numbers with decimals and uses scientific notation for large numbers. In many cases, you may want to format a cell with something other than the General number format.
The key thing to remember about number formatting is that it affects only how a value is displayed. The actual number remains intact, and any formulas that use a formatted number use the actual number.
An exception to this rule occurs if you specify the Precision as Displayed option on the Advanced tab of the Excel Options dialog box. If that option is in effect, formulas will use the values that are actually displayed in the cells as a result of a number format applied to the cells. In general, using this option is not a good idea because it changes the underlying values in your worksheet.
One more thing to keep in mind: If you use Excel's Find and Replace dialog box (choose Home⇒Editing⇒Find & Select⇒Find), characters that are displayed are a result of ...