To change the number format of cells:
Ensure that the Number tab is selected.
In the Category box, chose a number format type:
Currency: Formats numbers as currency, using the standard dollar sign ($).
Fixed: Formats numbers as fixed decimal numbers. Rounds numbers to a certain number of decimal places.
Percent: Displays numbers as percentages, using the percent sign (%). For example, 0.5 would be displayed as 50%.
Fraction: Displays decimal numbers as fractions. For example, 1.5 would be displayed as 1 1/2.
Scientific: Displays numbers in scientific notation. For example, 100 would be displayed as 1E+02.
Date: Converts numbers to dates.
Time: Converts numbers to times.
Select a format type from the Type box.
A preview of the format will appear in the Sample box.
When you have selected a format, click OK. The format of the selected cells will be changed.
Note: To quickly access the number formatting window, go to the Format menu, and click Number formatting.