Excel Lesson 4 Entering Worksheet Formulas

Transcription

1 Excel Lesson 4 Entering Worksheet Formulas Microsoft Office 2007: Introductory t 1

2 Objectives Enter and edit formulas. Distinguish between relative, absolute, and mixed cell references. Use the point-and-click method to enter formulas. Use the Sum button to view summary calculations. 2

3 Objectives (continued) Preview a calculation. Display formulas instead of results in the worksheet. Manually calculate formulas. 3

4 Vocabulary Absolute cell reference Formula Manual calculation Mixed cell reference Operand Operator Order of evaluation Point-and-click method Relative cell reference Sum button 4

5 What are Formulas? The equation used to calculate values in a cell is called a formula. Each formula begins with an equal sign (=). The results of the calculation appear in the cell in which the formula is entered. The formula itself appears in the formula bar. For example, if you enter the formula =8+6 in cell B3, the value 14 appears in the cell, and the formula E=8+6 appears in the formula bar when cell B3 is the active cell. 5

6 Entering a Formula Worksheet formulas consist of two components: operands and operators. An operand is a constant (text or number) or cell reference used in a formula. You can type cell references in uppercase (A1) or lowercase (a1). An operator is a symbol that indicates the type of calculation to perform on the operands, such as a plus sign (+) for addition. 6

7 Entering a Formula (continued) 7 Formulas can include more than one operator. The sequence used to calculate the value of a formula is called the order of evaluation. 1. Contents within parentheses are evaluated first. If there are multiple sets of parentheses, the innermost set of parentheses is evaluated first. 2. Mathematical operators are evaluated in the order of priority: Exponentiation, Positive or negative, Multiplication or division, Addition or subtraction. 3. If two or more operators have the same order of evaluation, the equation is evaluated from left to right.

8 Editing Formulas If you enter a formula with an incorrect structure, a dialog box appears, explaining the error and providing a possible correction. You can accept the correction or choose to correct the formula yourself. If you discover that you need to make a correction, you can edit the formula. Click the cell with the formula you want to edit. Press the F2 key or doubleclick the cell to enter editing mode. 8

9 Comparing Relative, Absolute, and Mixed Cell References Three types of cell references are used in formulas: relative, absolute, and mixed. A relative cell reference adjusts to its new location when copied or moved. Absolute cell references do not change when copied or moved to a new cell. To create an absolute cell reference, you insert a dollar sign ($) before the column letter and before the row number. Cell references that t contain both relative and absolute references are called mixed cell references. When formulas with mixed cell references are copied or moved, the row or column references preceded by a dollar sign do not change. 9

10 Creating Formulas Quickly To use the point-and-click method, simply click the cell instead of typing the cell reference. To use the Sum button, click the cell where you want the total to appear, and then click the Sum button. An outline appears around the range Excel selects. If you want to add numbers in a different range, drag to select those cells. Press the Enter key to complete the formula. The active cell displays the sum. 10

11 Previewing Calculations Whenever you select a range, the status bar shows the results of common calculations l for the selected cells. These summary calculations appear without your having to enter a formula. By default, Average, Count, and Sum appear in the status bar. You can also display Numerical Count, Minimum, and Maximum. 11

12 Showing Formulas in the Worksheet When creating a worksheet with many formulas, you may find it simpler to organize formulas and detect formula errors when all formulas are visible. To do this, click the Formulas tab on the Ribbon, and then click the Show Formulas button in the Formula Auditing group. The formulas replace the formula results in the worksheet. 12

13 Calculating Formulas Manually When you need to edit a worksheet with many formulas, you can specify manual calculation, which lets you determine when Excel calculates the formulas. The Formulas tab on the Ribbon contains all the buttons you need when working with manual calculations. To switch to manual calculation, click the Calculation Options button in the Calculation group on the Formulas tab, and then click Manual. 13

14 Summary 14 Formulas are equations used to calculate values in a cell, based on values referenced in other cells of the worksheet. Each formula begins with an equal sign and contains at least two operands and one operator. Formulas can include more than one operator. The order of evaluation determines the sequence used to calculate the value of a formula. If you enter a formula with an incorrect structure, Excel can correct the error for you, or you can choose to edit it yourself. To edit a formula, click the cell with the formula and then make changes in the formula bar. You can also double-click a formula and then edit the formula directly in the cell.

15 Summary (continued) Relative references adjust to a new location when copied or moved. Absolute references do not change, regardless of where they are copied or moved. Mixed references contain both relative and absolute references. Formulas can be created quickly using the point-andclick method. With this method, you insert a cell reference in a formula by clicking the cell rather than typing its column letter and row number. The Sum button in the Editing group on the Home tab inserts a formula with the SUM function, which adds the value of cells in the specified range. 15

16 Summary (continued) 16 The status bar shows a preview of common formulas, including Average, Count, and Sum, when you select a range of cells. You can choose which formula previews to show or hide. You can view the formulas in a worksheet, instead of the formula results, by clicking the Show Formulas button in the Formula Auditing group on the Formulas tab. Excel calculates formula results in a worksheet when you enter the formula, and recalculates the results whenever the cells used in that formula change. When you need to edit a worksheet with many formulas, you can click the Calculations Options button in the Calculation group on the Formulas tab, and then click Manual. When you want to calculate the formula results, click the Calculate Now button.