Lalo, from Odessa, TX asks:
Can you tell me what I can do to read an excel 2010 document in excel 2003?
Microsoft has, in fact, released several versions of its popular “Office” program.
According to Wikipedia, in October, 1990 Microsoft released a bundle which contained Word, Excel and Power Point – what would remain the three core programs of the Office suite, under the name of The Microsoft Office For Windows. This was followed by The Microsoft Office for Windows 3.0 in 1992, Microsoft Office 4.0 in 1994, Microsoft Office 95 in 1995 (of course), Microsoft Office 97 in 1997, Microsoft Office 2000 in 2000 and Microsoft Office XP (my personal favorite) in 2003.
One thing that was consistent through all of these iterations was the file extensions: .doc for Word, .xls for Excel and .ppt for Power Point. When Microsoft released the next two versions of the program, Office 2007 and Office 2010, they changed the basic file extensions to .docx, .xlsx and .pptx. This additional letter will change depend on what the file contains. For instance, a macro-enabled Power Point slideshow will have an extension of .pptm. A complete list of the new file extensions can be found at http://office.microsoft.com/en-us/help/introduction-to-new-file-name-extensions-HA010006935.aspx 
The downside of this is that it makes the created file incompatible with earlier versions of the program. There are two fixes for this however: one that can be performed when the file is created, and one when it is opened. I’ll use Word as my example here, since that’s what you asked about.
In order to create a Word 2010 document that can be opened using an earlier version of Word, open the save file dialog box. This can be done by clicking on the File tab, and then Save or Save as. On the window that opens, click on the save as type box, and choose what program you would like the document to be opened in.
Although this is labeled Word 2003, it will save as a format that can be opened with any other former Word program.
The other option, if you’ve received a .docx file and want to open it in an earlier version of Word, is to install the Microsoft Office compatibility pack, which can be found here: http://office.microsoft.com/en-us/word-help/open-a-word-2007-document-in-an-earlier-version-of-word-HA010044473.aspx 
The one drawback to this that you should be aware of is that any special formatting, such as macros may not be saved in the new document.
Hope this helps.