Applying a number format to a cell doesn't change the value but only how the value appears in the worksheet. Formatting can play a joke with you, e.g., the sum of values seems incorrect because Excel displays a limited number of decimal places, and their sum is not equal to the real sum.

The easiest way to enter a function into a formula is to use the Excel program's Insert Function dialog box.

The Excel TEXT function enables you to specify numbers and date format.

Excel formulas support many different operators. Operators are symbols that indicate what mathematical or logical operation a formula should perform. The following are the most common operators used in Excel.

If you simply need to perform a calculation, you can use the Formula bar as a calculator.

Formulas can refer to cells in other worksheets-and the worksheets don't even have to be in the same workbook. Excel uses a special type of notation to handle these types of references.

You can enter nonrelative references (absolute or mixed) manually by inserting dollar signs in the appropriate positions, or you can use a handy shortcut - F4 key.