Module Four: Formulas and Functions

Transcription

1 Page 4.1 Module Four: Formulas and Functions Welcome to the fourth lesson in the PRC s Excel Spreadsheets Course 1. This lesson concentrates on adding formulas and functions to spreadsheet to increase their usefulness. After starting with a difficult topic, it finishes up with two ways to make life easier, one by showing you how to find something on a spreadsheet and the other by checking your spelling for you. You will explore several pre-built sample spreadsheets and make modifications to each sample. The spreadsheets can be found on the accompanying student folder. Topics Use Built-in Functions Locate Data Correct Spelling Errors Exercises Exercise A - Change the Budget Spreadsheet Exercise B - Change the Auto Mileage Spreadsheet Summary Objectives Include functions like sum, average, min and max to make data more meaningful Find specific entries in large spreadsheets Spell check and correct spelling errors in a spreadsheet

2 Page 4.2 Use Built-in Functions You learned earlier in this course how to construct a formula. All formulas start with an equal sign and include the column header and row header as the cell reference, and of course a plus sign, minus sign or whatever you want to calculate; for example, =A1+B2. It would be very unusual for a spreadsheet to contain one or two or several formulas sitting in isolation. Consider setting up a budget in a spreadsheet. There is a left-right component, usually a time line that spans the weeks or the months of a year. At the end of every row is some kind of total. There is an up-down component within each of the weeks or months, usually categories of income and expense. At the bottom of income is a total, another at the bottom of expenses, and perhaps a net figure that subtracts expenses from income. At the lower right of such a set up is an item called a cross foot where the left-right totals are compared to the up-down totals. They should be the same and the cross foot is a check against errors in the budget. The picture you should get is, even when the arithmetic is mostly simple addition and subtraction, the spreadsheet can become a complicated set of related formulas. Your job is to visualize the connections among the formulas to make sure the spreadsheet behaves as you want. Never lose track of the fact that the spreadsheet is doing exactly what you tell it to do. If it misbehaves, it s not the fault of the spreadsheet. Excel does try to make your job easier. Based on feedback over the years, Microsoft has included many short cuts for building formulas. For example, suppose that budget spanned twelve months and you wanted a total for the year. You could enter something like =C5+D5+E5+F5+G5+H5+I5+J5+K5+L5+M5+N5 in a cell at the end of Row 5. What a pain, especially if you have to do it many times. Or you could enter =SUM(C5:N5) Adding a row of numbers is so common there is a function built into Excel to do just that. The function is read as, add all the entries in the range of cells from C5 through N5. Microsoft Excel includes many other formulas in the form of built-in functions. Examples include, =SUM( ) function adds a row or a column and provides the total result =AVERAGE( ) function finds the average of a row or column and provides the result =MIN( ) finds the smallest number in a series of cells =MAX( ) finds the largest number in a series of cells. Figure 4.1 The Sum button in the Home tab Editing group The =SUM( ) function is so commonly used there is a shortcut button on the Home tab, Editing group. It is the one with the Greek letter Sigma as pictured here. To use the SUM button, click below the column of numbers you want to total, then click the SUM button. Or, click to right of the row of numbers you want to total, then click the SUM button.

3 Page 4.3 When typing any of the above four functions, you must provide, within the parenthesis, the range of numbers you want to evaluate. If you wanted to average the numbers in B6 through B15, you would type =AVERAGE(B6:B15) into the Formula bar. Figure 4.2 The Formula Bar is located immediately above the spreadsheet Remember, when writing a formula: Start with the equal sign and then type the function name... followed by a left parenthesis, then type your beginning cell, then type a colon, then type the ending cell and finally conclude by typing a closing parenthesis and press the enter key Recall if you click on the red X you will erase all of the entry you are working on in the Formula bar it s a kind of Undo. If you click on the green check-mark it s the same as pressing the Enter key. It does not matter whether you use upper or lower case Excel will convert function names and cell references to upper case for you. Although it is rare to want to do so, the Formula bar can be turned off with a toggle switch selection under the View tab, Show/Hide group. It can also be turned on here in case you cannot seem to find it. The entries that occur between the parentheses of a function are called the arguments of the function. You must supply one or more arguments to make a function work. For example, the range B6:B15 is the argument given or entered for the AVERAGE( ) function, above. If a function requires more than one argument, the arguments are separated by commas. For example, =MOD(10,3) displays the value 1. MOD( ) is used to calculate remainders; the remainder of 10 divided by 3 is 1. MOD( ) requires two arguments separated by a comma. There are more than 300 functions contained in Excel; most of them more complex than SUM( ) or MAX( ). After some practice you will learn the arguments needed for the functions you use most frequently, but nobody knows all the arguments needed for all the functions contained in Excel. You will learn more about functions, and they way Excel helps with them, in a later lesson.

4 Page 4.4 Locate Data Often a spreadsheet can get very large. With 16,384 columns and 1,048,576 rows there is a lot of room beyond the view of your spreadsheet window. Making changes to a large spreadsheet has been simplified by the Find... and Replace... commands in the Home tab, Editing group. Figure 4.3 The Find & Select Menu showing the Find command under Home tab, Editing group For example, a spreadsheet which contains the names, address and phone numbers of your friends and family may require a change in certain area codes, but not all. Some people in area code 214 now have the new area code 972. First you must Find... the 214 people and then Replace... only those that really changed. Using the Find... or Replace... commands under the Edit Menu makes this job easier. The Replace... command is the preferred choice because it provides a find capability along with the replace function. The Find... command only locates the information in the spreadsheet.

5 Page 4.5 Figure 4.4 The Find dialog box only locates information In the area code change example, use the Replace... command to locate each and every 214 area code and if the persons area code did not change, click the Find Next button to locate the next person. However, if the person in your spreadsheet does need the new area code, click the Replace button to change from 214 to 972. Figure 4.5 The Replace dialog (Options open) box provides a text box for changes The Replace All button is reserved for those times when you want to blindly change every 214 area code to 972.

6 Page 4.6 Correct Spelling Errors Microsoft Excel includes a spell checking tool which has become an indispensable assistant when creating a spreadsheet. The spell checker in the spreadsheet program is the same one used in the word processing program. Figure 4.6 The Spelling button in the Review tab, Proofing group The Spelling command is located on the Review tab, Proofing group. Once a spelling error is found, you will be given a number of suggested spellings. Figure 4.7 The Spelling or Spell Checker dialog box Clicking on one of the suggested spelling in the Suggestions: text box, elevates that selection to the Change to: text box. Clicking on the Change or Change All button will replace the misspelled word with the correct word. If the word is really correct like a proper name or NYSE ticker symbol you can click the Ignore or Ignore All button to avoid any changes. If you would like to add the word to your Microsoft Excel dictionary click the Add button. If the Spelling... command could not find a suggested spelling, you may have to resolve the spelling error manually and type the new spelling into the Change to: text box and then click the Change button. You can also spell check a single word by first selecting/highlighting the word, then go to the Review tab, Proofing group and select the Spelling command. The same custom dictionary is used throughout Microsoft Excel. The following exercises will help solidify the topics taught in this lesson. The sample spreadsheets can be found on your computer hard drive. Explore the samples and have fun making changes.

7 Page 4.7 Exercise A - Change the Budget Spreadsheet In this exercise you will continue working on the budget spreadsheet from Lesson 3. You will add formulas and check for spelling errors. The spreadsheet can be found on your computer hard drive under the My Documents / Excel Files folder as 1.4budget.xls. Make changes to the spreadsheet and save it as 1.4budget_rev.xls. 1 Close all open Excel documents. 2 Using the Office Button Open sequence, open 1.4budget in the Excel Files folder To preserve the original spreadsheet, save the spreadsheet using a new name. 3 Using the Office Button Save As sequence, save the document as 1.4budget_rev in the same folder Add missing formulas 4 Click into cell B18 5 Add up the expenses for January by entering the function =SUM(B4:B17). Press Enter when done. This includes the empty cell, B17. Since the cell is empty, it will be evaluated as zero and the addition will be correct. This is not the case with all functions, and you have to be careful with how empty cells are treated to prevent subtle errors. It s considered good practice to use a range for the SUM( ) function that includes the cell immediately next to the cell that contains SUM( ). If a new category of expense is inserted at some future date, SUM( ) will automatically expand to include it as long as the insertion is within the range that SUM( ) is already using. If the empty cell is not included in the range for SUM( ) and the new category of expense is simply dropped into the empty row, SUM( ) won t pick it up. This is the cause of another subtle error very difficult to see and correct. 6 Click into cell C18 7 Click on the Sum button on the Standard toolbar. The function =SUM(C11:C17) appears. But this is not the formula that s needed it should be =SUM(C4:C17). The Sum button needs the boundaries of its range well-defined. In this example there is an empty cell, C10, in the middle of the range. You should always check to make sure the range is correct before pressing Enter. You do have the opportunity to edit (correct) the range in the Formula bar. Do that now by clicking in the Formula bar just to the right of C11, backspace out the 11, enter 4, and press Enter. 8 If the selected cell is no longer C18 use the arrow keys to return to cell C18. 9 Position the mouse pointer over the fill handle, the small black square in the bottom right corner of the cell border and drag the fill handle to the right to cell M18 and release the mouse button 10 Scroll left and down and click in cell B29 11 Click on the Sum button on the Standard toolbar. Double check function =SUM(B23:B28). Press Enter. 12 If the selected cell is no longer B29 use the arrow keys to return to cell B Drag cell B29 s fill handle to the right to cell M29 and release the mouse button 14 Scroll left and down and click in cell B32 This is where we find out how well the budget is doing. Enter a formula in B32 that will calculate cash flow; that is, the difference between total expenses and total income for the month. If income is greater than expense, the result should be a positive number. Try to work out the formula by yourself. Don t peek, the answer is in an italicized paragraph (like this one) lower on this page. 15 Type a formula in cell B32 that calculates cash flow (the difference between total expenses and total income for the month. Press Enter when you have completed your entry in cell B32

8 Page If the selected cell is no longer B32 use the arrow keys to return to cell B32 17 Drag cell B32 s fill handle to the right to cell M32 and release the mouse button Add Monthly Averages 18 Scroll up and right if necessary and click on cell N3 19 Using the Home tab Cells group Format Button Column Width sequence, set the column width to Type Monthly Average into cell N3 and press Enter. The text should overlap into cell O3 21 If the selected cell is no longer N3 use the arrow keys to return to cell N3 22 Click on the Bold button on the Home tab Font group. 23 Select Home Tab Alignment group. 24 Choose the icon that means Align Text Right. (you can hover you mouse pointer over the icons to see their meaning. 25 Still looking in the Home tab, Alignment group, click on the Wrap Text icon. 26 Click OK. Examine your result in cell N3 The formula that you should enter into B32 is =B29-B18 27 Click on cell N4 to select it and then click once in the Formula bar 28 Enter the following and then stop. Don t press Enter, just stop. =average( 29 Using the scroll bar, scroll to the left side of the spreadsheet 30 Click and drag from B4 through M4 and release the mouse button. You are selecting the range to be used by the Average function. Look at the Formula bar to see how the range is incorporated into the function. 31 Move your cursor back to the Formula bar and click once anywhere to the right of M4. Type the closing parenthetical element ). Press Enter. Figure 4.8 shows what your Formula bar should look like. Remember if you make a mistake and want to start over, just go to Undo in the Edit menu. Figure 4.8 The Average function in the Formula bar 32 If the selected cell is no longer N4 use the arrow keys to return to cell N4 33 Drag the fill handle of cell N4 down to cell N16 and release the mouse button Now look closely at your results. Does the average Rent look reasonable? There is that one dip in August makes you think perhaps the August entry is incorrect. What about the average Phone bill? All the Phone expenses are exactly the same, so the average should be the same as any one of the monthly payments. Drop down and look at Dues in Row 9. Every time Dues are paid it is exactly the same amount. So the average amount should be the same as any one of the monthly payments, just like Phone expenses. Or should it? Dues were not paid every month so that, on average, the monthly expense is $10, not $20. This is an example of how a function can treat an empty cell in a way that might cause an error. Enter a zero into L9, the cell for November Dues. What happened to the Monthly Average for Dues? Click on Undo in the Edit menu. You will learn more about the ins and outs of Excel functions in the next course. Meanwhile, we re going to undo a lot of what we just did to correct the spreadsheet as a whole. 34 Click on cell N16 and then click on the Copy button on the Home tab, Clipboard group 35 Click on cell N18 and then click on the Paste button on the Home tab, Clipboard group Since there are no empty cells in Row 18, this result should be okay. 36 Click on cell N29 and then click on the Paste button on the Home tab, Clipboard group 37 Click on cell N32 and then click on the Paste button on the Home tab, Clipboard group

9 Page Click and drag to select the range N4:N16. Press the Delete key on the keyboard. The next step will add simple formatting after all, we re dealing with dollars here 39 Click and drag in cells B4 through N19 all the expense numbers Figure 4.9 The Accounting shortcut or Dollar Sign formatting in the Home tab, Number group 40 Click on the Dollar Sign button on the Home, Number group, then click on one of the month names to clear the selection highlight. How does it look to you? Turn the gridlines off and look again. This formatting generates a strict columnar alignment such as that which occurred when using old 12-column accounting pads. Turn the gridlines back on again. 41 Click and drag in cells B4 through N19 to reselect the expense numbers 42 Select the Home tab, then click on the arrow in the bottom right hand corner under the Number group to open the Format Cells Dialog box 43 In Category drop down menu select Currency. Double check the Decimal places is 2 and the Currency symbol is $. Under Negative numbers select red without the ( ) and Click OK Same idea, slightly different presentation. 44 Click and drag in cells B23 through N32 to select the income numbers 45 Repeat Step Click on any one of the month names to clear the selection highlight. 47 Press Ctrl+Home to return to A1 Your completed spreadsheet should look like the one below in Figure Figure 4.10 Exercise A completed spreadsheet 48 Select the Office Button and then select the Save command Congratulations! You have successfully completed Exercise A

10 Page 4.10 Exercise B - Change the Auto Mileage Spreadsheet In this exercise you will continue working on the auto mileage spreadsheet from Lesson 3. You will add a new formulas and change font size, type and color. The spreadsheet can be found on your computer hard drive under My Documents / Excel Files as 1.4auto.xls. Make changes to the spreadsheet and save it as 1.4auto_rev.xls. 1 Close all open Excel documents. 2 Using the Office Button Open sequence, open 1.4auto in the Excel Files folder To preserve the original spreadsheet, save the spreadsheet using a new name. 3 Using the Office Button Save As sequence, save the document as 1.4auto_rev in the same folder The auto spreadsheet should now be open. Add some new information 4 Click in cell F5 and type Hours on the Road and press Enter 5 Move the mouse pointer over Row 3 s row heading and right click to reveal the shortcut menu 6 Select the Insert command on the pop-up menu (or you can go to the Home tab, Cells group and use the Insert Sheet Rows command) 7 Make sure there is a blank row between Miles per Gallon and Cost of Fuel, then click in cell D3. 8 Type Average Speed: in cell D3 and press the Tab key 9 Type 45 in cell E3 and press Enter 10 Click once in cell F7 Your intent is to enter a formula in F7 that will calculate Hours on the Road. Recall that distance = rate * time (d = r*t). To find time (t) divide both side of the equation by rate (r). This gives time = distance / rate (t = d/r). Consider the trip in Row 7. Can you find a cell that represents distance? Can you find a cell that contains rate? F7 is the cell that represents time. Using the equation above, what does it equal? F7 = C7/45 11 Enter the formula which will calculate Hours on the Road into F7. Remember, all formulas begin with the = sign. 12 Verify that cell F7 is still selected 13 Drag cell F7 s fill handle down to cell F55 and release the mouse button 14 Press Ctrl+Home to return to A1 Enhance the appearance of the new information 15 Change font styles and colors using buttons on the Home tab, Font group Cell D3 should be bold and italic, cell E3 should be red. Using the Home tab, Paragraph group make the cells D2:D6 aligned right andcells E6:F6 aligned right. 16 Select the cells in the range D7:D55

11 Page 4.11 Figure 4.11 The Decrease Decimal button on the Home tab, Number group 17 Click on the Decrease Decimal button in the Home tab, Number group several times until the column is displaying two decimal places 18 Repeat for the cells in the range F7:F55 19 Select the cells in the range E7:E55 and go to the Home tab, Number group. Click on the small arrow in the bottom right hand corner of the Number group to bring up the Format Cells dialog box 20 Click on the Number tab and select Currency under Category. Click OK. 21 Click on the column header for column C 22 Select Insert Sheet Columns under the Home tab, Cells group, Insert menu 23 Use the Home tab, Cells group, Format button, Column Width sequence to set the width of the new column to one. 24 Click on the row header for row 5 25 Select Insert Sheet Rows under the Home tab, Cells group, Insert menu There should now be an empty column between Destination City and Miles, and two empty rows below Cost of Fuel. 26 Click on cell E6. Type in the word Gallons and Press Enter. 27 Click on cell E7 if that is not the current cell selected. Click on the Format Painter button on the Home tab, Clipboard group 28 Click on cell E6. Figure 4.12 The Format button in the Home tab, Clipboard Group The Format Painter copies and pastes formats. Cell E6 should now be Font Size 12, Bold, Blue, and Aligned Right all the formatting attributes of cell E7. 29 Click on cell E7. On the Formula bar, click just to the left of the N in Needed, and then backspace out the word Gallons Press Enter. 30 Click on cell F6. Type in the words Cost of Press Enter. 31 Click on cell F7 if that is not the current cell selected. Click on the Format Painter button on the Home tab, Clipboard group 32 Click on cell F6. 33 Click on cell F7. On the Formula bar, click just to the left of the F in Fuel, and then backspace out the words Cost of Press Enter. 34 Click on cell G6. Type in the words Hours on Press Enter. 35 Click on cell G7 if that is not the current cell selected. Click on the Format Painter button on the Home tab, Clipboard group 36 Click on cell G6. 37 Click on cell G7. On the Formula bar, click just to the left of the t in the, and then backspace out the words Hours on Press Enter. 38 Set the column width for columns E, F, and G to Press Ctrl+Home to return to cell A1. Your spreadsheet should look like the one in Figure 4.13.

12 Page 4.12 Figure 4.13 Exercise B completed spreadsheet 40 Select the Office Button and then select the Save command Do a Find 41 Using the Home tab, Editing group, Find & Select menu, Find sequence, find the distance between Bismarck and Fargo (hint: type Fargo in the Find what: box and then click on Find Next) Correct spelling 42 Click on the Select All hot spot to select the whole spreadsheet Remember, the Select All hot spot is the small square above the row 1 header and to the left of the column A header 43 Click on the Spellingbutton on the Review tab, Proofing group and correct any misspellings in the spreadsheet 44 Click on the Save button on the Quick Access toolbar 45 Select the Office Button and then select the Exit command to close Microsoft Excel Congratulations! You have successfully completed Exercise B

13 Page 4.13 Summary Now you can... Add formulas and built-in function to a spreadsheet. Build a formula which includes a range of cells. Find the location of a specific item in a spreadsheet Invoke the spell checker to correct spelling errors in your spreadsheet. You have explored how to create more complex spreadsheets and use functions like sum and average to further enhance your spreadsheets. You also practiced more formatting to make your spreadsheets both attractive and readable. In the next lesson you will move away from a spreadsheet s capability to calculate values using formulas and functions and toward a spreadsheet s other strength, keeping track of (mostly) text data items using the spreadsheet like a database. NOTES