1. Technology Basics Creating Worksheet Formulas

2. 2 Understand Formulas Equations used to calculate values in cells are called formulas. Formulas consist of two components: An operand An operator All formulas begin with an equal sign (=). Formulas may contain from one to several cell references.

3. 3 Commonly Used Formula Operators Mathematical OperationOperator Addition+ (plus sign) Subtraction― (minus sign) Multiplication* (asterisk) Division/ (forward slash) Percent% (percent sign) This table shows some of the operators typically used in Excel formulas.

4. 4 Evaluating Complex Formulas FormulaResult =6+4*46+16=22 =6*4+224÷2=26 =6-4/26-2=4 =6/2+43+4=7 =(6+4+*410*4=40 =(6*4)-(10/2)24-5+19 Formulas with more than one operator are called complex formulas. The order of evaluation for complex formulas is shown below. Some samples of complex formulas are shown at right. Multiplication and Division are performed before addition and subtraction. Calculations are performed from left to right. Parentheses can be used to change the order of evaluation.

5. 5 Create a Formula You can enter a cell address into a formula in two different ways: Key the cell address. The column reference can be uppercase or lower- case. Point to the cell with the pointer. As you enter cell references, Excel color codes the cell borders and the cell references. The formula is displayed in the Formula bar as you type it. When you press Enter, the result of the formula will display in the cell.

6. 6 Entering a Formula This figure shows a formula being entered into cell E3. Note the color coding for cells B3, C3, and D3 and the same color coding for each cell reference used in the formula in cell E3. Also note that the formula being entered is shown in the Formula bar. Cell borders and cell references are color coded.

7. 7 Show the Formula Result Once you press the Enter key, the result of the formula calculation will display in the cell containing the formula. If you select the cell, as shown here, the formula itself is visible in the Formula bar.

8. 8 Identify and Correct Formula Errors If Excel cannot properly perform a calculation, an error value will display in the cell with the formula. The error may occur because A cell contains text instead of a numeric value. A cell referenced in the formula contains an error. A formula tries to divide by zero. The cell is not wide enough to contain the result value. Excel has an AutoCorrect feature that tries to correct errors that occur while typing the formula.

9. 9 Use the Help System to Find Formula Errors You can use the Excel Help system to find information on formulas and finding errors in formulas. Click the Help menu, then choose Microsoft Excel Help. Click the Contents tab to see a list of topics, as shown to the right. Click the Plus sign for the Creating and Correcting Formulas topic to see additional topics on formulas.

10. 10 Use Trace Error to Fix Problems in Formulas Excel has a Trace Error feature that you can use to obtain information on formula errors. To use it, click the pointer in a cell that has an error code displayed. Point to the Trace Error button that will display to the left of the cell. When you point to the Trace Error button, a ScreenTip will appear with information about the error. Click the down arrow on the Trace Error button to see the menu shown here. Click the Show Calculation Steps option.

11. 11 The Evaluate Formula Windows When you click the Show Calculation Steps option on the Trace Error menu, this dialog box will appear showing you what values are being used for the formula. You can clearly see here that one of the fields contains a text value instead of a number.

12. 12 Use the AutoSum Feature AutoSum allows you to quickly identify a range of cells to be used in a formula. When you click the AutoSum button, Excel determines the most logical column or row of adjacent cells to sum. After identifying the cell range, Excel creates a function formula to calculate the sum of the cell range. Be aware that Excel does not always properly identify the correct cell range. If so, you can drag to identify the correct range, then press Enter to fix the formula.

13. 13 A Function Formula The equal sign The function name The argument A function formula contains three parts. Note that a colon is used to indicate that this is a cell range.

14. 14 An AutoSum Example In this figure, cell E6 was selected and then the AutoSum button was clicked. Excel scanned the worksheet and then drew an animated marquee around the cell range E3 # E5, indicating that this is the range to be summed in cell E6. However, the intent was to sum cells B6 through D6. To correct this, click in cell B6, drag through to cell D6, and press the Enter key. Excel will automatically correct the formula to read =SUM(B6:D6).

15. 15 Use the AutoFill Command to Enter Formulas AutoFill can be used to copy formulas up, down, left, or right. Cell references are formatted as relative cell references by default. That means that, when the formula is copied to another cell, the cell references will be adjusted relative to their new location. Use the fill handle to drag a formula in a selected cell to a new adjacent cell or multiple adjacent cells. Examine the formula for the new cells in the Formula bar to see the updated cell references.

16. 16 Use Absolute Cell References An absolute cell reference does not change when a formula is copied or moved to a new location. You create an absolute reference by inserting a dollar sign ($) before the column or row designator. For example, =B5+$A$3 If this formula was copied to a new cell, the B5 reference would automatically update to a new cell number, but the $A$3 would not change at all. A mixed cell reference is created when the column or the row is absolute, but not both of them. For example, $A3

17. 17 Display Formulas in the Worksheet Data and formulas should always be checked to ensure that they are both accurate. In a worksheet with many formulas, clicking each cell with a formula to display it in the Formula bar can be tedious and time consuming. It is easier to simply display all formulas. Press and hold down the Ctrl key, then press the single left quotation mark (usually upper left on the keyboard). All formulas will be displayed on the worksheet grid.

18. 18 Worksheet with Formulas Displayed This figure shows a worksheet in which the formulas have been displayed, making it much easier to find and verify them.

19. 19 Audit Formulas on the Worksheet In a worksheet with many formulas, verifying all cell references can be very time consuming. The Formula Audit toolbar contains tools that make it easy to trace cell references. It can also display precedent and dependent cells. Open the Formula Auditing toolbar shown below from the View/Toolbars menu and option.

20. 20 A Worksheet with Auditing In this figure, cell C10 was selected and the Trace Precedents button was clicked on the Formula Audit toolbar. The arrow that runs from cell B7 # D7 marks these cells as the ones that provide the data to the formula. When the Trace Dependents button is clicked, the arrows are drawn from C10 to cells E3 # E7 to show that these cells depend on the data in cell C10.