# 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.