Here are a couple ways to make sure you aren’t sending the boss a spreadsheet with the obvious Formula errors in it.

What’s an obvious Formula error? #DIV/0!, #NAME?, #NULL!,#NUM!, #REF!, #VALUE!

Error Checking with the Auditing Toolbar
The first button on the auditing toolbar provides an “Error Checking” function. Simply click it and Excel will let you know if your spreadhsheet contains any errors.

To make the Auditing Toolbar visible: Click View->ToolBars-> and choose Formula Auditing

Error Checking with Conditional Formatting
Automatically turning cells with errors to a different color using conditional formatting is an easy way to help reduce spreadsheet errors while you work. Errors are easy to detect as they are created, and also easily viewable from a quick scan of the spreadsheet. Read how in the post Highlighting Spreadsheet Errors.