By design, Apple uses its own Numbers (.numbers) file format, while Excel uses the XLSX file format, or for earlier spreadsheets, the XLS format. You can open XLSX files in Numbers, but you can ...

Learn how to change the default file format for saves in Word, Excel, and PowerPoint, so that you do not need to change it every time.

If Microsoft Excel fails to recognize a file in the XLSX or XLS format, the data contained in the file could be corrupted. When you open a corrupted workbook in Excel, the program should ...

Regardless of which format your workbook follows, there's no denying that both of these file extensions are one of the most universally accepted file formats on popular platforms.

However, since an XLR file is a spreadsheet file similar to Microsoft Excel files, you can use Excel to open it, then you can resave it using the newer Excel file format, making the file more ...