Chapter 32. Making Your Worksheets Error-Free

IN THIS CHAPTER

How to identify and correct common formula errors

Using Excel auditing tools

Using formula AutoCorrect

Tracing cell relationships

Checking spelling and related features

It goes without saying that you want your Excel worksheets to produce accurate results. Unfortunately, it's not always easy to be certain that the results are correct — especially if you deal with large, complex worksheets. This chapter introduces the tools and techniques available to help identify, correct, and prevent errors.

32.1. Finding and Correcting Formula Errors

Making a change in a worksheet — even a relatively minor change — may produce a ripple effect that introduces errors in other cells. For example, accidentally entering a value into a cell that previously held a formula is all too easy to do. This simple error can have a major impact on other formulas, and you may not discover the problem until long after you make the change — or you may never discover the problem.

Formula errors tend to fall into one of the following general categories:

• Syntax errors: You have a problem with the syntax of a formula. For example, a formula may have mismatched parentheses, or a function may not have the correct number of arguments.

• Logical errors: A formula doesn't return an error, but it contains a logical flaw that causes it to return an incorrect result.

• Incorrect reference errors: The logic of the formula is correct, but the formula uses an incorrect cell reference. As a simple example, the range reference in a Sum formula may not include all the data that you want to sum.

• Semantic errors: An example is a function name that is spelled incorrectly. Excel will attempt to interpret it as a name and will display the #NAME? error.

• Circular references: A circular reference occurs when a formula refers to its own cell, either directly or indirectly. Circular references are useful in a few cases, but most of the time, a circular reference indicates a problem.

• Array formula entry error: When entering (or editing) an Array formula, you must press Ctrl+Shift+Enter to enter the formula. If you fail to do so, Excel doesn't recognize the formula as an Array formula, and you may get an error or incorrect results.

• Incomplete calculation errors: The formulas simply aren't calculated fully. Microsoft has acknowledged some problems with Excel's calculation engine in some versions of Excel. To ensure that your formulas are fully calculated, press Ctrl+Alt+Shift+F9.

Syntax errors are usually the easiest to identify and correct. In most cases, you'll know when your formula contains a syntax error. For example, Excel won't permit you to enter a formula with mismatched parentheses. Other syntax errors also usually result in an error display in the cell.

The following sections describe common formula problems and offers advice on identifying and correcting them.

32.1.1. Mismatched parentheses

In a formula, every left parenthesis must have a corresponding right parenthesis. If your formula has mismatched parentheses, Excel usually won't permit you to enter it. An exception to this rule involves a simple formula that uses a function. For example, if you enter the following formula (which is missing a closing parenthesis), Excel accepts the formula and provides the missing parenthesis.

=SUM(A1:A500

A formula may have an equal number of left and right parentheses, but the parentheses may not match properly. For example, consider the following formula, which converts a text string such that the first character is uppercase and the remaining characters are lowercase. This formula has five pairs of parentheses, and they match properly.

=UPPER(LEFT(A1))&RIGHT(LOWER(A1),LEN(A1)−1)

The following formula also has five pairs of parentheses, but they are mismatched. The result displays a syntactically correct formula that simply returns the wrong result.

=UPPER(LEFT(A1)&RIGHT(LOWER(A1),LEN(A1)−1))

Often, parentheses that are in the wrong location will result in a syntax error, which is usually a message that tells you that you entered too many or too few arguments for a function.

Using Formula AutoCorrect When you enter a formula that has a syntax error, Excel attempts to determine the problem and offers a suggested correction. The accompanying figure shows an example of a proposed correction. Be careful when accepting corrections for your formulas from Excel because it doesn't always guess correctly. For example, I entered the following formula (which has mismatched parentheses): =AVERAGE(SUM(A1:A12,SUM(B1:B12)) Excel then proposed the following correction to the formula: =AVERAGE(SUM(A1:A12,SUM(B1:B12))) You may be tempted to accept the suggestion without even thinking. In this case, the proposed formula is syntactically correct — but not what I intended. The correct formula is =AVERAGE(SUM(A1:A12),SUM(B1:B12))

Excel can help you out with mismatched parentheses. When you're editing a formula and you move the cursor over a parenthesis, Excel displays it (and its matching parenthesis) in bold for about one-half second. In addition, Excel color codes pairs of nested parentheses while you are editing a formula.

32.1.2. Cells are filled with hash marks

A cell is filled with a series of hash marks (#) for one of two reasons:

• The column is not wide enough to accommodate the formatted numeric value. To correct it, you can make the column wider or use a different number format (see Chapter 24).

• The cell contains a formula that returns an invalid date or time. For example, Excel doesn't support dates prior to 1900 or the use of negative time values. A formula that returns either of these values results in a cell filled with hash marks. Widening the column won't fix it.

32.1.3. Blank cells are not blank

Some Excel users have discovered that by pressing the spacebar, the contents of a cell seem to erase. Actually, pressing the spacebar inserts an invisible space character, which isn't the same as erasing the cell.

For example, the following formula returns the number of nonempty cells in range A1:A10. If you "erase" any of these cells by using the spacebar, these cells are included in the count, and the formula returns an incorrect result.

=COUNTA(A1:A10)

If your formula doesn't ignore blank cells the way that it should, check to make sure that the blank cells are really blank cells. Here's how to search for cells that contain only blank characters:

32.1.4. Extra space characters

If you have formulas or use procedures that rely on comparing text, be careful that your text doesn't contain additional space characters. Adding an extra space character is particularly common when data has been imported from another source.

Excel automatically removes trailing spaces from values that you enter, but trailing spaces in text entries are not deleted. It's impossible to tell just by looking at a cell whether it contains one or more trailing space characters.

The TRIM function removes leading spaces, trailing spaces, and multiple spaces within a text string. Figure 32.1 shows some text in column A. The formula in B1, which was copied down the column is

=TRIM(A1)=A1

This formula returns FALSE if the text in column A contains leading spaces, trailing spaces, or multiple spaces. In this case, the word Dog in cell A3 contains a trailing space.

Tracing Error Values Often, an error in one cell is the result of an error in a precedent cell. For help in identifying the cell causing an error value to appear, activate the cell that contains the error and then choose Formulas Formula Auditing Error Checking Trace Error. Excel draws arrows to indicate which cell is the source of the error. After you identify the error, choose Formulas Formula Auditing Remove Arrows to get rid of the arrow display.

32.1.5. Formulas returning an error

A formula may return any of the following error values:

• #DIV/0!

• #N/A

• #NAME?

• #NULL!

• #NUM!

• #REF!

• #VALUE!

The following sections summarize possible problems that may cause these errors.

Excel allows you to choose how error values are printed. To access this feature, display the Page Setup dialog box and click the Sheet tab. You can choose to print error values as displayed (the default), or as blank cells, dashes, or #N/A. To display the Page Setup dialog box, click the dialog box launcher of the Page Layout Page Setup group.

32.1.5.1. #DIV/0! errors

Division by zero is not a valid operation. If you create a formula that attempts to divide by zero, Excel displays its familiar #DIV/0! error value.

Because Excel considers a blank cell to be zero, you also get this error if your formula divides by a missing value. This problem is common when you create formulas for data that you haven't entered yet, as shown in Figure 32.2. The formula in cell D2, which was copied to the cells below it, is

=(C2-B2)/C2

This formula calculates the percent change between the values in columns B and C. Data isn't available for months beyond May, so the formula returns a #DIV/0! error.

To avoid the error display, you can use an IF function to check for a blank cell in column C:

= IF(C2=0,"",(C2-B2)/C2)

This formula displays an empty string if cell C2 is blank or contains 0; otherwise, it displays the calculated value.

Another approach is to use an IFERROR function to check for any error condition. The following formula, for example, displays an empty string if the formula results in any type of error:

=IFERROR((C2-B2)/C2,"")

=IF(ISERROR((C2-B2)/C2),"",(C2-B2)/C2)

32.1.5.2. #N/A errors

The #N/A error occurs if any cell referenced by a formula displays #N/A.

The #N/A error also occurs when a LOOKUP function (HLOOKUP, LOOKUP, MATCH, or VLOOKUP) can't find a match.

32.1.5.3. #NAME? errors

The #NAME? error occurs under these conditions:

• The formula contains an undefined range or cell name.

• The formula contains text that Excel interprets as an undefined name. A misspelled function name, for example, generates a #NAME? error.

• The formula uses a worksheet function that's defined in an add-in, and the add-in is not installed.

Excel has a bit of a problem with range names. If you delete a name for a cell or range and the name is used in a formula, the formula continues to use the name, even though it's no longer defined. As a result, the formula displays #NAME?. You may expect Excel to automatically convert the names to their corresponding cell references, but this doesn't happen.

32.1.5.4. #NULL! errors

A #NULL! error occurs when a formula attempts to use an intersection of two ranges that don't actually intersect. Excel's intersection operator is a space. The following formula, for example, returns #NULL! because the two ranges don't intersect:

=SUM(B5:B14 A16:F16)

The following formula doesn't return #NULL! but displays the contents of cell B9, which represents the intersection of the two ranges:

=SUM(B5:B14 A9:F9)

32.1.5.5. #NUM! errors

A formula returns a #NUM! error if any of the following occurs:

• You pass a non-numeric argument to a function when a numeric argument is expected.

• You pass an invalid argument to a function. For example, this formula returns #NUM!:

  =SQRT(−12)

  
  

• A function that uses iteration can't calculate a result. Examples of functions that use iteration are IRR and RATE.

• A formula returns a value that is too large or too small. Excel supports values between −1E-307 and 1E+307.

32.1.5.6. #REF! errors

A #REF! error occurs when a formula uses an invalid cell reference. This error can occur in the following situations:

• You delete the row column of a cell that is referenced by the formula. For example, the following formula displays a #REF! error if row 1, column A, or column B is deleted:

  =A1/B1

  
  

• You delete the worksheet of a cell that is reference by the formula. For example, the following formula displays a #REF! error if Sheet2 is deleted:

  =Sheet2!A1

  
  

• You copy a formula to a location that invalidates the relative cell references. For example, if you copy the following formula from cell A2 to cell A1, the formula returns #REF! because it attempts to refer to a nonexistent cell.

  =A1-1

  
  

• You cut a cell (choose Home Clipboard Cut) and then paste it to a cell that's referenced by a formula. The formula will display #REF!.

32.1.5.7. #VALUE! errors

A #VALUE! error is very common and can occur under the following conditions:

• An argument for a function is of an incorrect data type, or the formula attempts to perform an operation using incorrect data. For example, a formula that adds a value to a text string returns the #VALUE! error.

• A function's argument is a range when it should be a single value.

• A custom worksheet function is not calculated. You can press Ctrl+Alt+F9 to force a recalculation.

• A custom worksheet function attempts to perform an operation that is not valid. For example, custom functions can't modify the Excel environment or make changes to other cells.

• You forget to press Ctrl+Shift+Enter when entering an Array formula.

Pay Attention to the Colors When you edit a cell that contains a formula, Excel color-codes the cell and range references in the formula. Excel also outlines the cells and ranges used in the formula by using corresponding colors. Therefore, you can see at a glance the cells that are used in the formula. You also can manipulate the colored outline to change the cell or range reference. To change the references used in a formula, drag the outline's border or fill handle (at the lower right of the outline). This technique is often easier than editing the formula.

32.1.6. Absolute/relative reference problems

As I describe in Chapter 10, a cell reference can be relative (for example, A1), absolute (for example, $A$1), or mixed (for example, $A1 or A$1). The type of cell reference that you use in a formula is relevant only if the formula will be copied to other cells.

A common problem is using a relative reference when you should use an absolute reference. As shown in Figure 32.3, cell C1 contains a tax rate, which is used in the formulas in column C. The formula in cell C4 is

=B4+(B4*$C$1)

Notice that the reference to cell C1 is an absolute reference. When the formula is copied to other cells in column C, the formula continues to refer to cell C1. If the reference to cell C1 were a relative reference, the copied formulas would return an incorrect result.

32.1.7. Operator precedence problems

As I describe in Chapter 10, Excel has some straightforward rules about the order in which mathematical operations are performed. When in doubt (or when you simply need to clarify your intentions), you should use parentheses to ensure that operations are performed in the correct order. For example, the following formula multiplies A1 by A2 and then adds 1 to the result. The multiplication is performed first because it has a higher order of precedence.

=1+A1*A2

The following is a clearer version of this formula. The parentheses aren't necessary, but in this case, the order of operations is perfectly obvious.

=1+(A1*A2)

Notice that the negation operator symbol is exactly the same as the subtraction operator symbol. This, as you may expect, can cause some confusion. Consider these two formulas:

=−3^2
=0-3^2

The first formula, as expected, returns 9. The second formula, however, returns −9. Squaring a number always produces a positive result, so how is it that Excel can return the −9 result?

In the first formula, the minus sign is a negation operator and has the highest precedence. However, in the second formula, the minus sign is a subtraction operator, which has a lower precedence than the exponentiation operator. Therefore, the value 3 is squared, and then the result is subtracted from 0 (zero), which produces a negative result.

Using parentheses, as shown in the following formula, causes Excel to interpret the operator as a minus sign rather than a negation operator. This formula returns −9.

=-(3^2)

32.1.8. Formulas are not calculated

If you use custom worksheet functions written in VBA, you may find that formulas that use these functions fail to get recalculated and may display incorrect results. To force a single formula to be recalculated, select the cell, press F2, and then press Enter. To force a recalculation of all formulas, press Ctrl+Alt+F9.

32.1.9. Actual versus displayed values

You may encounter a situation in which values in a range don't appear to add up properly. For example, Figure 32.4 shows a worksheet with the following formula entered into each cell in the range B2:B4:

=1/3

Cell B5 contains the following formula:

=SUM(B2:B4)

All the cells are formatted to display with three decimal places. As you can see, the formula in cell B5 appears to display an incorrect result. (You may expect it to display 0.999.) The formula, of course, does return the correct result. The formula uses the actual values in the range B2:B4 not the displayed values.

You can instruct Excel to use the displayed values by selecting the Set Precision as Displayed check box of the Advanced section of the Excel Options dialog box. (Choose File Excel Options to display this dialog box.)

Be very careful with the Set Precision as Displayed option. This option also affects normal values (nonformulas) that have been entered into cells. For example, if a cell contains the value 4.68 and is displayed with no decimal places (that is, 5), selecting the Precision as Displayed check box converts 4.68 to 5.00. This change is permanent, and you can't restore the original value if you later clear the Set Precision as Displayed check box. A better approach is to use the ROUND function to round off the values to the desired number of decimal places.

32.1.10. Floating point number errors

Computers, by their very nature, don't have infinite precision. Excel stores numbers in binary format by using eight bytes, which can handle numbers with 15-digit accuracy. Some numbers can't be expressed precisely by using eight bytes, so the number stores as an approximation.

To demonstrate how this lack of precision may cause problems, enter the following formula into cell A1:

=(5.1-5.2)+1

The result should be 0.9. However, if you format the cell to display 15 decimal places, you discover that Excel calculates the formula with a result of 0.899999999999999. This result occurs because the operation in parentheses is performed first, and this intermediate result stores in binary format by using an approximation. The formula then adds 1 to this value, and the approximation error is propagated to the final result.

In many cases, this type of error doesn't present a problem. However, if you need to test the result of that formula by using a logical operator, it may present a problem. For example, the following formula (which assumes that the previous formula is in cell A1) returns FALSE:

=A1=.9

One solution to this type of error is to use the ROUND function. The following formula, for example, returns TRUE because the comparison is made by using the value in A1 rounded to one decimal place.

=ROUND(A1,1)=0.9

Here's another example of a "precision" problem. Try entering the following formula:

=(1.333-1.233)−(1.334-1.234)

This formula should return 0, but it actually returns −2.220446E-16 (a number very close to zero).

If that formula is in cell A1, the following formula returns Not Zero.

=IF(A1=0,"Zero","Not Zero")

One way to handle these "very close to zero" rounding errors is to use a formula like this:

=IF(ABS(A1)<1E-6,"Zero","Not Zero")

This formula uses the less-than (<) operator to compare the absolute value of the number with a very small number. This formula returns Zero.

32.1.11. "Phantom link" errors

You may open a workbook and see a message like the one shown in Figure 32.5. This message sometimes appears even when a workbook contains no linked formulas. Often, these phantom links are created when you copy a worksheet that contains names.

First, try choosing File Info Edit Links to Files to display the Edit Links dialog box. Then select each link and click Break Link. If that doesn't solve the problem, this phantom link may be caused by an erroneous name. Choose Formulas Defined Names Name Manager and scroll through the list of names. If you see a name that refers to #REF!, delete the name. The Name Manager dialog box has a Filter button that lets you filter the names. For example, you can filter the lists to display only the names with errors.

32.2. Using Excel Auditing Tools

Excel includes a number of tools that can help you track down formula errors. This section describes the auditing tools built in to Excel.

32.2.1. Identifying cells of a particular type

The Go to Special dialog box (as shown in Figure 32.6) is a handy tool that enables you to locate cells of a particular type. To display this dialog box, choose Home Editing Find & Select Go to Special.

You can use the Go to Special dialog box to select cells of a certain type, which can often help you identify errors. For example, if you choose the Formulas option, Excel selects all the cells that contain a formula. If you zoom the worksheet out to a small size, you can get a good idea of the worksheet's organization (see Figure 32.7). To zoom a worksheet, use the zoom controls on the right side of the status bar. Or, press Ctrl while you move the scroll wheel on your mouse.

Selecting the formula cells may also help you spot a common error: namely, a formula that has been replaced accidentally with a value. If you find a cell that's not selected amid a group of selected formula cells, chances are good that the cell previously contained a formula that has been replaced by a value.

32.2.2. Viewing formulas

You can become familiar with an unfamiliar workbook by displaying the formulas rather than the results of the formulas. To toggle the display of formulas, choose Formulas Formula Auditing Show Formulas. You may want to create a second window for the workbook before issuing this command. This way, you can see the formulas in one window and the results of the formula in the other window. Choose View Window New Window to open a new window.

You can also press Ctrl+` (the accent grave key, typically located above the Tab key) to toggle between Formula view and Normal view.

Figure 32.8 shows an example of a worksheet displayed in two windows. The window on the top shows Normal view (formula results), and the window on the bottom displays the formulas. Choosing View Window View Side by Side, which allows synchronized scrolling, is also useful for viewing two windows. (See Chapter 4 for more information about this command.)

32.2.3. Tracing cell relationships

To understand how to trace cell relationships, you need to familiarize yourself with the following two concepts:

• Cell precedents: Applicable only to cells that contain a formula, a formula cell's precedents are all the cells that contribute to the formula's result. A direct precedent is a cell that you use directly in the formula. An indirect precedent is a cell that isn't used directly in the formula but is used by a cell that you refer to in the formula.

• Cell dependents: These formula cells depend upon a particular cell. A cell's dependents consist of all formula cells that use the cell. Again, the formula cell can be a direct dependent or an indirect dependent.

For example, consider this simple formula entered into cell A4:

=SUM(A1:A3)

Cell A4 has three precedent cells (A1, A2, and A3), which are all direct precedents. Cells A1, A2, and A3 each have a dependent cell (cell A4), and they're all direct dependents.

Identifying cell precedents for a formula cell often sheds light on why the formula isn't working correctly. Conversely, knowing which formula cells depend on a particular cell is also helpful. For example, if you're about to delete a formula, you may want to check whether it has any dependents.

32.2.3.1. Identifying precedents

You can identify cells used by a formula in the active cell in a number of ways:

• Press F2. The cells that are used directly by the formula are outlined in color, and the color corresponds to the cell reference in the formula. This technique is limited to identifying cells on the same sheet as the formula.

• Display the Go to Special dialog box. (Choose Home Editing Find & Select Go to Special.) Select the Precedents option and then select either Direct Only (for direct precedents only) or All Levels (for direct and indirect precedents). Click OK, and Excel selects the precedent cells for the formula. This technique is limited to identifying cells on the same sheet as the formula.

• Press Ctrl+[. This selects all direct precedent cells on the active sheet.

• Press Ctrl+Shift+{. This selects all precedent cells (direct and indirect) on the active sheet.

• Choose Formulas Formula Auditing Trace Precedents. Excel will draw arrows to indicate the cell's precedents. Click this button multiple times to see additional levels of precedents. Choose Formulas Formula Auditing Remove Arrows to hide the arrows. Figure 32.9 shows a worksheet with precedent arrows drawn to indicate the precedents for the formula in cell C13.

32.2.3.2. Identifying dependents

You can identify formula cells that use a particular cell in a number of ways:

• Display the Go to Special dialog box. Select the Dependents option and then select either Direct Only (for direct dependents only) or All Levels (for direct and indirect dependents). Click OK. Excel selects the cells that depend upon the active cell. This technique is limited to identifying cells on the active sheet only.

• Press Ctrl+]. This selects all direct dependent cells on the active sheet.

• Press Ctrl+Shift+}. This selects all dependent cells (direct and indirect) on the active sheet.

• Choose Formulas Formula Auditing Trace Dependents. Excel will draw arrows to indicate the cell's dependents. Click this button multiple times to see additional levels of dependents. Choose Formulas Formula Auditing Remove Arrows to hide the arrows.

32.2.4. Tracing error values

If a formula displays an error value, Excel can help you identify the cell that is causing that error value. An error in one cell is often the result of an error in a precedent cell. Activate a cell that contains an error value and then choose Formulas Formula Auditing Error Checking Trace Error. Excel draws arrows to indicate the error source.

32.2.5. Fixing circular reference errors

If you accidentally create a circular reference formula, Excel displays a warning message — Circular Reference — with the cell address, in the status bar, and also draws arrows on the worksheet to help you identify the problem. If you can't figure out the source of the problem, choose Formulas Formula Auditing Error Checking Circular References. This command displays a list of all cells that are involved in the circular references. Start by selecting the first cell listed and then work your way down the list until you figure out the problem.

32.2.6. Using background error-checking feature

Some people may find it helpful to take advantage of the Excel automatic error-checking feature. This feature is enabled or disabled via the Enable Background Error Checking check box, found on the Formulas tab of the Excel Options dialog box, shown in Figure 32.10. In addition, you can use the check boxes in the Error Checking Rules section to specify which types of errors to check.

When error checking is turned on, Excel continually evaluates the formulas in your worksheet. If a potential error is identified, Excel places a small triangle in the upper-left corner of the cell. When the cell is activated, a Smart Tag appears. Clicking this Smart Tag provides you with options. Figure 32.11 shows the options that appear when you click the Smart Tag in a cell that contains a #DIV/0! error. The options vary, depending on the type of error.

In many cases, you will choose to ignore an error by selecting the Ignore Error option. Selecting this option eliminates the cell from subsequent error checks. However, all previously ignored errors can be reset so that they appear again. (Use the Reset Ignored Errors button in the Formulas tab of the Excel Options dialog box.)

You can choose Formulas Formula Auditing Error Checking to display a dialog box that describes each potential error cell in sequence, much like using a spell-checking command. This command is available even if you disable background error checking. Figure 32.12 shows the Error Checking dialog box. This dialog box is modeless: that is, you can still access your worksheet when the Error Checking dialog box is displayed.

The error-checking feature isn't perfect. In fact, it's not even close to perfect. In other words, you can't assume that you have an error-free worksheet simply because Excel doesn't identify any potential errors! Also, be aware that this error-checking feature won't catch a very common type of error: namely, overwriting a formula cell with a value.

32.2.7. Using the Excel Formula Evaluator

Formula Evaluator lets you see the various parts of a nested formula evaluated in the order that the formula is calculated. To use Formula Evaluator, select the cell that contains the formula and then choose Formula Formula Auditing Evaluate Formula to display the Evaluate Formula dialog box (see Figure 32.13).

Click the Evaluate button to show the result of calculating the expressions within the formula. Each click of the button performs another calculation. This feature may seem a bit complicated at first, but if you spend some time working with it, you'll understand how it works and see the value.

Excel provides another way to evaluate a part of a formula:

The highlighted portion of the formula displays the calculated result. You can evaluate other parts of the formula or press Esc(ape) to cancel and return your formula to its previous state.

Be careful when using this technique because if you press Enter (rather than Esc), the formula will be modified to use the calculated values.

32.3. Searching and Replacing

Excel has a powerful search-and-replace feature that makes it easy to locate information in a worksheet or across multiple worksheets in a workbook. As an option, you can also search for text and replace it with other text.

To access the Find and Replace dialog box, start by selecting the range that you want to search. If you select any single cell, Excel searches the entire sheet. Choose Home Editing Find & Select Find (or, click Ctrl+F). You'll see the Find and Replace dialog box shown in Figure 32.14. If you're simply looking for information in the worksheet, click the Find tab. If you want to replace existing text with new text, use the Replace tab. Also note that you can use the Options button to display (or hide) additional options. The dialog box shown in the figure displays these additional options.

32.3.1. Searching for information

Enter the information to search for in the Find What text box and then specify any of the following options.

• Within drop-down list: Specify where to search (the current sheet or the entire workbook).

• Search drop-down list: Specify the direction (by rows or by columns).

• Look In drop-down list: Specify what cell parts to search (formulas, values, or comments).

• Match Case check box: Specify whether the search should be case sensitive.

• Match Entire Cell Contents check box: Specify whether the entire cell contents must be matched.

• Format button: Click to search for cells that have a particular formatting (see the upcoming "Searching for formatting" section).

Click Find Next to locate the matching cells one at a time or click Find All to locate all matches. If you use the Find All button, the Find and Replace dialog box expands to display the addresses of all matching cells in a list (see Figure 32.15). When you select an entry in this list, Excel scrolls the worksheet so that you can view it in context.

After using Find All, press Ctrl+A to select all the found cells.

32.3.2. Replacing information

To replace text with other text, use the Replace tab in the Find and Replace dialog box. Enter the text to be replaced in the Find What field and then enter the new text in the Replace With field. Specify other options as described in the previous section.

Click Find Next to locate the first matching item and then click Replace to do the replacement. When you click the Replace button, Excel then locates the next matching item. To override the replacement, click Find Next. To replace all items without verification, click Replace All. If the replacement didn't occur as you planned, you can use the Undo button on the Quick Access toolbar (or press Ctrl+Z).

To delete information, enter the text to be deleted in the Find What field but leave the Replace With field empty.

32.3.3. Searching for formatting

From the Find and Replace dialog box, you can also locate cells that contain a particular type of formatting. As an option, you can replace that formatting with another type of formatting. For example, assume that you want to locate all cells that are formatted as bold and then change that formatting to bold and italic. Follow these steps:

You can also find formatting based on a particular cell. In the Find Format dialog box, click the Choose Format from Cell button and then click the cell that contains the formatting you're looking for.

The Find and Replace dialog box cannot find background color formatting in tables that was applied using table styles, or formatting that is applied based on conditional formatting.

32.4. Spell Checking Your Worksheets

If you use a word processing program, you probably take advantage of its spell checker feature. Spelling mistakes can be just as embarrassing when they appear in a spreadsheet. Fortunately, Microsoft includes a spell checker with Excel.

To access the spell checker, choose Review Proofing Spelling, or press F7. To check the spelling in just a particular range, select the range before you activate the spell checker.

If the spell checker finds any words it does not recognize as correct, it displays the Spelling dialog box, shown in Figure 32.17.

The Spelling dialog box works similarly to other spell checkers with which you may be familiar. If Excel encounters a word that isn't in the current dictionary or that is misspelled, it offers a list of suggestions. You can respond by clicking one of these buttons:

• Ignore Once: Ignore the word and continues the spell check.

• Ignore All: Ignore the word and all subsequent occurrences of it.

• Add to Dictionary: Add the word to the dictionary.

• Change: Change the word to the selected word in the Suggestions list.

• Change All: Change the word to the selected word in the Suggestions list and change all subsequent occurrences of it without asking.

• AutoCorrect: Add the misspelled word and its correct spelling (which you select from the list) to the AutoCorrect list.

32.5. Using AutoCorrect

AutoCorrect is a handy feature that automatically corrects common typing mistakes. You can also add words to the list that Excel corrects automatically. The AutoCorrect dialog box appears in Figure 32.18. To access this feature, choose File Options. In the Excel Options dialog box, click the Proofing tab and then click the AutoCorrect Options button.

This dialog box has several options:

• Correct TWo INitial CApitals: Automatically corrects words with two initial uppercase letters. For example, BUdget is converted to Budget. This mistake is common among fast typists. You can click the Exceptions button to specify a list of exceptions to this rule.

• Capitalize First Letter of Sentences: Capitalizes the first letter in a sentence. All other letters are unchanged.

• Capitalize Names of Days: Capitalizes the days of the week. If you enter monday, Excel converts it to Monday.

• Correct Accidental Use of cAPS LOCK key: Corrects errors caused if you accidentally pressed the CapsLock key while typing.

• Replace Text as You Type: AutoCorrect automatically changes incorrect words as you type them.

Excel includes a long list of AutoCorrect entries for commonly misspelled words. In addition, it has AutoCorrect entries for some symbols. For example, (c) is replaced with ©, and (r) is replaced with ®. You can also add your own AutoCorrect entries. For example, if you find that you frequently misspell the word January as Janruary, you can create an AutoCorrect entry so that it's changed automatically. To create a new AutoCorrect entry, enter the misspelled word in the Replace box and the correctly spelled word in the With field. You can also delete entries that you no longer need.

You also can use the AutoCorrect feature to create shortcuts for commonly used words or phrases. For example, if you work for a company named Consolidated Data Processing Corporation, you can create an AutoCorrect entry for an abbreviation, such as cdp. Then, whenever you type cdp, Excel automatically changes it to Consolidated Data Processing Corporation. Just make sure that you don't use a combination of characters that might normally appear in your text.

You can use the AutoFormat as You Type tab of the AutoCorrect dialog box to control a few other automatic settings in Excel.

Use the Smart Tags tab to make Excel show Smart Tags — similar to hyperlinks — for certain types of data in your worksheets. The types of Smart Tags Excel recognizes vary depending on the types of software that are installed on your system.

The Math AutoCorrect tab contains shortcuts used to enter symbols when working in the Equation Editor (see Chapter 22).