In Excel number formats tell your spreadsheet what data you're using. Use custom number formatting in Excel to improve spreadsheets.

Here are a few tips for getting the best results with number formatting:

**Apply number formatting to an entire column**: If you're planning to use one column for a certain type of data, like dates or percentages, you may find it easiest to select the entire column by clicking the column letter and applying the desired number formatting. This way, any data you add to this column in the future will already have the correct number format. Note that the header row usually won't be affected by number formatting.**Double-check your values after applying number formatting**: If you apply number formatting to existing data, you may have unexpected results. For example, applying**percentage**(%) formatting to a cell with a value of 5 will give you 500%, not 5%. In this case, you'd need to retype the values correctly in each cell.- If you reference a cell with number formatting in a formula, the spreadsheet may automatically apply the same number formatting to the new cell. For example, if you use a value with currency formatting in a formula, the calculated value will also use the currency number format.
- If you want your data to appear
**exactly as entered,**you'll need to use the**text**number format. This format is especially good for numbers you don't want to perform calculations with, such as phone numbers, zip codes, or numbers that begin with 0, like**02415**. For best results, you may want to apply the text number format before entering data into these cells.

The **Increase Decimal** and **Decrease Decimal** commands allow you to control how many decimal places are displayed in a cell. These commands don't change the value of the cell; instead, they display the value to a set number of decimal places.

Decreasing the decimal will display the value rounded to that decimal place, but the actual value in the cell will still be displayed in the formula bar.

The **Increase/Decrease Decimal** commands don't work with some number formats, like **Date** and **Fraction**.

- Open our practice workbook.
- In cell
**D2**, type today's date and press**Enter**. - Click cell
**D2**and verify that it is using a**Date**number format. Try changing it to a different date format (for example,**Long Date**). - In cell
**D2**, use the**Format Cells**dialog box to choose the**14-Mar-12**date format. - Change the sales tax rate in cell
**D8**to the**Percentage**format. - Apply the
**Currency**format to all of**column B**. - In cell
**D8**, use the**Increase Decimal**or**Decrease Decimal**command to change the number of decimal places to**one**. It should now display**7.5%**. - When you're finished, your spreadsheet should look like this: