Applies to
Microsoft Excel 2002 Microsoft Office Excel 2003

Sometimes using a regular old calculator can feel as tedious as pushing beads across an abacus. With Microsoft Excel, you can do math by typing simple formulas to add, divide, multiply, and subtract. You can also total all the values in a column with a formula that updates its result if values change later on. What could be easier?

Imagine that Excel is open and you're looking at the "Entertainment" section of a budget for household expenses. Cell C6 in the worksheet is empty; the amount spent for CDs (compact discs) in February hasn't been entered yet.

Begin with an equal sign

Two CDs purchased in February cost $12.99 and $16.99. The total of these two values is the CD expense for the month.

You do math in Excel by typing simple formulas into cells. Excel formulas always begin with an equal sign (=). Here's the formula typed into cell C6 to add 12.99 and 16.99:

=12.99+16.99

The plus sign (+) is a math operator that tells Excel to add the values.

If you wonder later on how you got this result, the formula is visible in the formula bar near the top of the worksheet whenever you select cell C6 again.

Type the formula in cell C6.

Press ENTER to display the formula result.

Any time you select cell C6, the formula appears in the formula bar.

Use other math operators

To do more than add, you would use other math operators as you type formulas into worksheet cells.

Math operator	Example
Add (+)	=10+5
Subtract (-)	=10-5
Multiply (*)	=10*5
Divide (/)	=10/5

You would start each formula with an equal sign and use a minus sign (-) to subtract, an asterisk (*) to multiply, and a forward slash (/) to divide.

Total all the values in a column

To add up the total of expenses for January, you wouldn't have to type all those values again. Instead you could use a prewritten formula, called a function.

1. Get the January total by selecting cell B7, and then clicking AutoSum on the Standard toolbar.
   This enters the SUM function, which adds up all the values in a range of cells.

   Tip   To save time, use the function whenever you have more than a few values to add up, so that you don't have to type the formula.

2. Press ENTER to display the SUM function result, 95.94, in cell B7.

   Tip   The formula =SUM(B3:B6) appears in the formula bar whenever cell B7 is selected.

B3:B6 is the information, called the argument, that tells the SUM function what to add. By using a cell reference (B3:B6) instead of the values in those cells, Excel can automatically update results if values change later on. The colon (:) in B3:B6 indicates a cell range in column B, rows 3 through 6. The parentheses are required to separate the argument from the function.

Select cell B7 and then click the AutoSum button.

A color marquee surrounds the cells in the formula, and the formula appears in cell B7.

Any time you select cell C6, the formula appears in the formula bar. Press ENTER to display the result in cell B7.

Select cell B7 to display the formula in the formula bar.

Copy a formula instead of creating a new one

Sometimes it's easier to copy formulas than to create new ones. In the example below, you'll see how to copy the January formula and use it to add up the February expenses.

1. Select cell B7, which contains the January formula, and then position the mouse pointer over the lower-right corner of the cell until the black cross (+) appears.
2. Drag the fill handle over cell C7. When the fill handle is released, the February total 126.93 appears in cell C7.
   The formula =SUM(C3:C6) is visible in the formula bar near the top of the worksheet whenever cell C7 is selected.
3. After the formula is copied, the Auto Fill Options button appears to give you some formatting options. In this case you wouldn't need to do anything with the button options. The button disappears when you next make an entry in any cell.

   Note   You can drag the fill handle to copy formulas only into cells that are next to each other, either horizontally or vertically.

Drag the black cross from the cell containing the formula to the cell where the formula will be copied, and then release the fill handle.

Auto Fill Options button appears but requires no actions.

Now you have a basic idea of how to use Excel as a calculator. So stop counting your fingers and toes and make some formulas.