A common question I get asked is if older versions of MS Office programs can open documents created in the newest version of Office 2013.
The quick answer is YES, however you will need to download an OOXML strict converter from Microsoft to open Office 2013 documents in Office 2010.
You can find the converter here:
The above support article also addresses conversions from Office 2013 to Office 2007 and Office 2003.
NB: Always remember that when you click on a link in an article or email that the URL you see in the email or article is exactly the same as the URL that is appearing in your browser address bar.