Computer Literacy BASICS Key Applications Module Lesson 18 — Creating Formulas and Charting Data Computer Literacy BASICS

Computer Literacy BASICS Objectives Understand and create formulas in a worksheet. Identify and correct formula errors. Use the AutoSum feature. Understand and use function formulas. Understand and use relative and absolute cell references. Computer Literacy BASICS

Computer Literacy BASICS Objectives (cont.) Create a chart from worksheet data. Edit chart data and change chart formats and options. Interpret data from worksheets and charts. Computer Literacy BASICS

Computer Literacy BASICS Vocabulary Absolute cell reference Argument Chart Embedded chart Formulas Function formula Mathematical functions Mixed cell reference Operand Operator Order of evaluation Relative cell references Statistical functions Computer Literacy BASICS

Computer Literacy BASICS Formulas Equations used to calculate values in cells are called formulas. Formulas consist of two components: An operand, which is a number or cell reference. An operator, which is a mathematical symbol. All formulas begin with an equal sign (=). Formulas may contain one or several cell references. Computer Literacy BASICS

Operators Used in Excel Formulas Computer Literacy BASICS

Computer Literacy BASICS Order of Evaluation Multiplication and division are performed before addition and subtraction. Calculations are per-formed from left to right. Parentheses can be used to change the order of evaluation. Formulas with more than one operator, such as the ones above, are complex formulas and use the order of evaluation rules shown to calculate a value. Computer Literacy BASICS

Computer Literacy BASICS Creating a Formula There are two ways to enter a cell address into a formula: Key the cell address (using uppercase or lowercase for the column reference). Point to the cell with the mouse pointer to add it to the formula. As you enter cell references, Excel color codes the cell borders and the cell references. Computer Literacy BASICS

Creating a Formula (cont.) Formula Bar Formula Cell references are color coded 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. Computer Literacy BASICS

Computer Literacy BASICS Editing a Formula There are three ways to edit a formula: Double-click the cell and then edit the formula in the cell. Select the cell, press F2, and then edit the formula in the cell. Select the cell and then edit the formula in the Formula Bar. Computer Literacy BASICS

Computer Literacy BASICS 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. Computer Literacy BASICS

Computer Literacy BASICS Trace Errors Excel has an AutoCorrect feature to correct some errors that occur while entering a formula. Excel also has a Trace Error feature: Click the pointer in a cell that has an error code displayed. Point to the Trace Error button to the left of the cell with an error to display a ScreenTip with information about the error. Click the down arrow on the Trace Error button to display this menu. Computer Literacy BASICS

The Evaluate Formula Dialog Box Clicking the Show Calculation Steps option in the shortcut menu opens the Evaluate Formula dialog box where you can often see the problem with the formula. Computer Literacy BASICS

Relative Cell References By default, when you create formulas, the cell references are formatted as relative cell references. This means that when the formula is copied to another cell, the cell references will be adjusted relative to the formula’s new location, which is helpful when you need to repeat the same formula for several columns or rows. Computer Literacy BASICS

Absolute Cell References An absolute cell reference does not change when a formula is copied or moved to a new location. To create an absolute reference, insert a dollar sign ($) before the column or row designator: =B5+$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. Computer Literacy BASICS

Computer Literacy BASICS Mixed Cell References A mixed cell reference is created when the column or the row is absolute, but not both of them: $A3 When formulas with mixed cell references are copied or moved: The row or column references that are preceded by a dollar sign do not change. The row or column references not preceded by a dollar sign adjust relative to the cell to which they are moved. Computer Literacy BASICS

Computer Literacy BASICS AutoSum 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, but you must check to make sure the range for the formula is appropriate. After identifying the cell range, Excel creates a function formula to calculate the sum of the cell range. Computer Literacy BASICS

Parts of a Function Formula A function formula, such as AutoSum, contains three parts: The equal sign required to start all formulas The function name The arguments The arguments are the values, cell references, or text that act as an operand. Equal sign Function name Argument Computer Literacy BASICS

Computer Literacy BASICS Function Formulas Excel includes more than 300 functions for performing calculations. It has mathematical functions and trigonometric functions. It has statistical functions. Functions can be entered by keying them from the keyboard. Or you can enter them using the Insert Function and Function Arguments dialog boxes. Computer Literacy BASICS

Common Excel Functions Mathematical Functions Statistical Functions =PRODUCT =ROUND =ROUNDUP =ROUNDDOWN =SUM =AVERAGE =COUNT =MAX =MEDIAN =MIN Computer Literacy BASICS

The Insert Function Dialog Box The Insert Function dialog box can be used to help create a function formula. Click the Insert Function button on the Formula Bar to display the dialog box. Insert Function Computer Literacy BASICS

Selecting a Function Formula Enter a description of what you want to do in the Search for a function text box and then click Go. A list of functions will appear in the Select a function section of the box, and the function you want should be selected. A brief description of the function and an example of it will appear beneath this window. Computer Literacy BASICS

The Function Arguments Dialog Box Select your function (if necessary) and click OK to open the Function Arguments dialog box. The Function Arguments dialog box guides you through the process of building a formula that contains a function. Constructing an AVERAGE function formula Computer Literacy BASICS

Computer Literacy BASICS The Average Function The Average function is a statistical function. It displays the average value of the range identified in the argument. Equal sign Argument Function formula to calculate the average of the values in cells B4, B6, and B8 Function name Computer Literacy BASICS

Computer Literacy BASICS The Sum Function The Sum function is a mathematical function. It calculates the sum of the range identified in the argument. The function formula =SUM(B2:B8) calculates the total of the values in cells B2 through B8. Computer Literacy BASICS

Computer Literacy BASICS The Count Function The Count function is a statistical function. It displays the number of cells with numerical values in the argument range. The function formula =COUNT(B4:B10) displays the result 7 if all the cells in the argument contained a numeric value. You can edit the range of cells displayed in the Function Arguments dialog box by selecting the cells. Computer Literacy BASICS

Minimum and Maximum Functions MIN and MAX are statistical functions. The MIN function displays the smallest value in the argument range, so =MIN(D4:D12) would display the smallest numerical value in cells D4 through D12. The MAX function displays the largest value in the argument range, so =MAX(D4:D12) would display the largest numerical value in cells D4 through D12. Computer Literacy BASICS

Computer Literacy BASICS Charts A chart is a graphic representation of worksheet data. Charts can make the data more interesting and easier to read and comprehend. Excel provides several chart types that you can choose from. The chart type that you select will depend on the data being represented by the chart. Computer Literacy BASICS

Computer Literacy BASICS Chart Types Computer Literacy BASICS

Computer Literacy BASICS Parts of a Chart Data series Chart title Plot area Value axis title Chart area Value axis Category axis Legend Category axis title Computer Literacy BASICS

Computer Literacy BASICS Using the Chart Wizard The Chart Wizard makes it simple to create professional-looking charts from Excel data. Charts can be created on their own worksheet or on the sheet with the data. Charts created on the same sheet as the data that created the chart are called embedded charts. Before using the Chart Wizard, you must select the data to be used. Computer Literacy BASICS

Computer Literacy BASICS The Chart Wizard Click the Chart Wizard button on the Standard toolbar to start the Wizard. The Chart Wizard offers options and asks you questions in a series of dialog boxes to help create your chart. Computer Literacy BASICS

Computer Literacy BASICS Editing Chart Data There will be times when the data used to create a chart changes. You do not need to create a new chart when this happens. Update the data and Excel will update the chart automatically to reflect the new data. Computer Literacy BASICS

Changing Chart Formats Many parts of a chart, such as the chart title and axis titles, are positioned as text boxes. You can select the text box and change the format of the data. Once the text box is selected, select the text and use the Formatting toolbar to change font attributes and alignment. You can also right-click on the text box to display a shortcut menu with other formatting options. Computer Literacy BASICS

Computer Literacy BASICS Chart Options To change chart options, you must first select the chart. With the chart selected, open the Chart menu and then select Chart Options. The Chart Options dialog box has six tabs for various chart features. Click a tab and examine the options available for each tab. Modify the chart layout as needed. Computer Literacy BASICS

The Chart Options Dialog Box There are six tabs on the Chart Options dialog box that allow you to change many of the chart features. Computer Literacy BASICS

Changing the Chart Type After creating and examining your chart, you may decide that the chart type you have chosen is not the best way to present your data. You can quickly and easily change the chart type: Select Chart Type from the Chart menu. When the Chart Type dialog box opens, select the new chart type and subtype and then click OK. Excel will convert your existing chart to the new type. Computer Literacy BASICS

Drawing Conclusions from Worksheet Data The results of a worksheet are only accurate if correct data and formulas have been used. Once the accuracy has been verified, ask yourself: What does the worksheet tell me? What conclusions can I draw from it? Computer Literacy BASICS

Interpreting Graphical Data Examine your charts carefully to be sure that the data is accurate and labeled accurately. Make certain that the chart type you have chosen best represents the information you are trying to present. Computer Literacy BASICS

Computer Literacy BASICS Summary One of the primary uses for Excel spreadsheets is to perform calculations. Formulas are equations with numbers, cell references, and operators that tell Excel how to perform the calculations. All formulas begin with =. To enter the cell references in a formula, you can key the cell address or you can point and click the cell you want to reference. Computer Literacy BASICS

Computer Literacy BASICS Summary (cont.) If Excel cannot perform a calculation, an error value will display. The Trace Error button will display and can help guide you in troubleshooting the problem. You can then edit the formula directly in the cell or in the Formula Bar. Computer Literacy BASICS

Computer Literacy BASICS Summary (cont.) If you do not want the cell reference to change when the formula is moved or copied to a new location, the cell reference must be formatted as an absolute cell reference. The AutoFill feature enables you to quickly copy formulas to adjacent cells. The cell references are adjusted relative to the formula’s new location. Computer Literacy BASICS

Computer Literacy BASICS Summary (cont.) The AutoSum feature enables you to quickly identify a range of cells and enter a formula. Functions are special formulas that do not require operators. Excel provides more than 300 built-in functions to help you perform mathematical, statistical, and other functions. Computer Literacy BASICS

Computer Literacy BASICS Summary (cont.) The Average function displays the average of the range identified in the argument. The Sum function totals the values in the specified range of cells. The Count function displays the number of cells with numerical values in the argument range. Computer Literacy BASICS

Computer Literacy BASICS Summary (cont.) The Minimum and Maximum functions display the smallest or the largest number contained in the range identified in the argument. A chart displays the worksheet data visually and often helps the audience understand and interpret the information more clearly. Computer Literacy BASICS

Computer Literacy BASICS Summary (cont.) When the worksheet data is changed, the chart is automatically updated to reflect those changes. Chart formats, options, and types can be changed at any time, even after the chart has been created. Computer Literacy BASICS

Computer Literacy BASICS Summary (cont.) Excel worksheets and charts convey information and allow you to draw logical conclusions from the data, but you must ensure that the data is accurate and that you know what the values represent to make a correct assessment. Computer Literacy BASICS