Open, View and Print 2007-2013 file formats in older Excel versions
Download the Excel Viewer from the Microsoft site
With Excel Viewer, you can open, view, and print Excel workbooks, even if you don't have Excel installed. You can also copy data from Excel Viewer to another program. However, you cannot edit data, save a workbook, or create a new workbook. This download is a replacement for Excel Viewer 97 and all previous Excel Viewer versions.
Here are the links to the Word and PowerPoint viewer
Open, Edit, Print and Save 2007-2013 file formats in older Excel versions
Download the Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint
Open, edit, and save documents, workbooks, and presentations in the file formats new to Microsoft Office Word, Excel, and PowerPoint 2007-2013.
Note: With this Compatibility Pack installed you also have a few more options in he Save/Save As dialog.