Tracing Errors

Suppose you have a worksheet in which there is an error (such as #VALUE! or #DIV/0! or #NUM! or any number of other errors), but you are not quite sure what caused it. As you may know, this is not that odd of an occurrence. It is possible (and sometimes common) to have a single error propagated throughout an entire worksheet. If you don't know where the error is coming from, the easiest way to find out is to follow these steps:

1. Select one of the cells that contains an error.
2. Choose Auditing from the Tools menu. (In Excel 2002 or Excel 2003 you choose Formula Auditing from the Tools menu.) Excel displays a submenu.
3. Select Trace Error from the submenu.

Excel tracks down the source of the error, using red auditing arrows. You can now make your corrections and get rid of at least one error in your workbook.

Excel 2002 and Excel 2003 have another handy way you can track down errors. If a cell contains an error value, the upper-left corner of the cell will have a small green triangle in it. If you select the cell, and information tool tip appears near this green triangle. When you click on the tool tip you see a menu that includes several different helpful suggestions, including an option to Trace Error. If you choose this option, you get the same result as if you followed the steps outlined above.

You should note that you can use the Trace Error auditing tool only to track down the source of obvious error conditions, meaning those that display an error condition such as #NA or #NAME. Subtle errors, such as adding together the wrong values or using the wrong function, cannot be detected by Excel and must be tracked down manually.