When using Excel functions play an important role in finding values for a range of cells. Learn all about using functions in Excel.

A **function** is a **predefined formula** that helps perform common mathematical functions. Functions save you the time of writing lengthy formulas. You could use an Excel function called **Average**, for example, to quickly find the average of range of numbers. Or you could use the **Sum** function to find the sum of a cell range. Excel 2003 contains many different functions.

Each function has a specific order, called **syntax**, which must be strictly followed for the function to work correctly.

Syntax order:

- All functions begin with the = sign.
- After the = sign, define the
**function name**(e.g., Sum). - Add one or more
**arguments**—numbers, text, or cell references—enclosed by parentheses. If there is more than one argument, separate each by a comma.

An example of a function with one argument that adds a range of cells, B3 through B10:

An example of a function with **more than one argument** that calculates the average of numbers in a range of cells, B3 through B10 and C3 through C10:

Excel literally has hundreds of different **functions** to assist with your calculations. Building formulas can be difficult and time consuming. Excel's functions can save you a lot of time and headaches.