Enter a formula

A formula is an expression which calculates the value of a cell. Functions are predefined formulas and are already available in Excel.

To enter a formula, execute the following steps.

1. Select a cell. 
2. To let Excel know that you want to enter a formula, type an equal sign (=). 
3. For example, type the formula A1+A2.  
   
4. Change the value of cell A1 to 3.
   

Tip: instead of typing A1 and A2, simply select cell A1 and cell A2.