# Formulas & Functions

The ability to perform calculations is one of the purposes of using a spreadsheet application. Some examples of the types of calculations that can be done include:

• totals
• subtotals
• count
• average
• standard deviation

After completing this module, you should be able to:

• Construct a formula using cell references and named ranges.
• Describe the standard order of operations.
• Explain the difference between formulas and functions.
• Execute a function.

## Arithmetic Operators

Excel uses the standard arithmetic operators and follows the order of operations as described below:

 Order Arithmetic Operator Details First Parentheses Computations enclosed in parentheses are performed first. Second Exponents Computations involving exponents are performed next. Third Multiplication and Division Computations with multiplication and division are performed in the order in which they occur from left to right. Last Addition and Subtraction Computations with addition and subtraction are performed in the order in which they occur from left to right.

## Formulas

Formulas are instructions for performing calculations. The best way to construct a formula is to use cell references instead of typing numbers in the formula. This enables Excel to automatically update the results of formulas when you change values in the cells referenced.

Note: All formulas and functions start with the equal sign ( = ).

## Functions

Functions are preset formulas that are included in the Excel application. Many times a function will simplify the formulas that you would otherwise enter manually.

For example, you can use the SUM function to add the values in a range of cells.  The function would be similar to the following =SUM(E4:E15).  If you were to manually enter a formula to perform this same calculation, you would have to type =E4+E5+E6+E7+E8+E9+E10+E11+E12+E13+E14+E15

To view the list of functions in Office 2007 click on the Formula tab and select Insert Function from the under the Function group.

Note:
If you already know what function you want to use, you can simply select the corresponding function button from the Function group.

Functions perform calculations by using specific values, called the arguments.  The particular order by which the calculations are performed is called the syntax. Like formulas, the syntax of a function always begins with the equal sign ( = ) followed by the function name and then the arguments.

Note:
The arguments of a function must be contained within parenthesis.