A function in Excel is a built-in formula that performs a mathematical operation or returns information specified by the formula. There are multiple ways you can create a function. You can insert functions manually (by typing them), or you can use the Insert Function dialog box. The Insert Function dialog box eliminates the possibility of a typing error, so it is the recommended method.

Function versus Formulas

	A	B
1		Jan
2	Entertain ment	45
3	ice swimming	245
4	yodel course	45
5	kangaroo wrestling	12
6	rodeo	542
7	TOTAL	889

The function is the built-in formula provided by Excel. The formula is the function with its arguments. For example, when I added the cells B2 – B6 to get the Total of $889 I get the formula total which in Excel looks like (B2:B6)

Writing Functions with the Insert Function Dialog Box

Determining what functions are available, what function you should be using, and what you need to include in the function is easier with the Insert Function dialog box. The Insert Function dialog box will display a listing of all functions or categories of functions available with Excel. As you select a function (as in the following graphic), a sample of the function appears at the bottom of the dialog box. As you make your selection, the Insert Function dialog box will request certain types of information. You simply select the cells where that information is located.

Place the cell pointer on the cell where the formula should be added – in this instance I put it in B7 (above where it says 889)
From the Insert menu, select Function…
The Insert Function dialog box appears.
From the Or select a category pull-down list, select the appropriate function category or All
From the Select a function scroll box, select the desired function – in my case above I chose ‘SUM’
A description of the selected function appears beneath the Select a function scroll box. and in this instance I selected SUM and it reads

SUM(number1,number2,…)

Adds al the numbers in a range of cells.

Click OK
The Function Arguments dialog box appears.

In the text boxes, type the data to be in the function IN MY EXAMPLE (or if you highlighted the column with your cursor it will show too)

To hide the dialog box so you can select cell ranges with the mouse rather than type them, click COLLAPSE DIALOG.
To restore the dialog box, click RESTORE DIALOG.

Click OK and the total for Jan = 889 (cell B7)

Exercise One

Copy the data from my entertainment budget into a new spreadsheet. Using Insert > Function > Average What number do you get in cell B7?

Exercise Two

Using Insert > Function > SUMSQ What number do you get in cell B7?

About the Function Arguments Dialog Box

The Function Arguments dialog box helps you to enter worksheet functions. As you type the function, the Function Arguments dialog box displays the name of the function, the function arguments, a description of the function and its arguments, and the result of the function. Once you have entered a function, you can further edit it using the Function Arguments dialog box.

To access the Function Arguments dialog box:

Select a cell containing a function
On the Formula bar, click INSERT FUNCTION
The Function Arguments dialog box appears.

Writing Formulas and Functions with the Point Method

Formulas based on cell references can be "written" by pointing to the cells rather than typing the cell entries. This "point" method can help reduce the chance of error in the formulas and sometimes may make more sense. The point method may not work as well when the cells in question are located in different areas of the worksheet, but the method can be used then as well.

The key to the point method is to point to click the cells to be included and to type the operators where appropriate.

The following examples provide step-by-step instructions for a simple addition of two cells and for adding a range of cells.

Adding Cells Together

Place the insertion point in the cell where the results should be displayed
To start the function, press [=]
Point and click the first cell to be added
Press [+]
Point and click the next cell to be added
Repeat steps 4-5 as necessary
Press [Enter] or [return] for example(=C2+C6) = 80

Exercise Three

What is the result of adding together =B4+C6+D2+G4?

Adding a Range of Cells with the SUM Function: Option 1

Place the insertion point in the cell where the results should be displayed
To start the function, press [=]
Type SUM(
Point and click the first cell in the range to be added
Press [:]
Point and click the last cell to be added
Type ) for example(=SUM(E3:E6)) = 9931
Press [Enter] or [return]

Exercise Four

Using the above Option 1 what is the total for the range (B3:H3)

Adding a Range of Cells with the SUM Function: Option 2

Place the cell pointer in the cell where the results should be displayed
To start the function, press [=]
Type SUM(
Click and drag the mouse to select the range of cells to be added
Type )
Press [Enter] or [return]

Exercise Five

Using the above Option 2 what is the total for the range (C2:C8)?

Exercise Six

Go to one fast food site (McDonalds and others are not showing their information today)

Burger King = http://www.bk.com/ > Our Menu > select your alleged “food”> select Printable Format and see below

Entering Data and Formulas:

Set up your Excel spreadsheet like the one above. You will enter the calories in column B and fat calories in column C.

To figure out total calories, total fat calories, and total non-fat calories, you can use the AutoSum button or write a formula. To figure out the total percentage of fat, divide total calories by total fat calories

We will continue with this on Wednesday when we get percentages and do some graphs