Image credit: Apple Inc
You can export iWork documents in the format of their equivalent applications in Microsoft’s Office suite, that is, Pages in Word, Numbers as Excel documents and Keynote as PowerPoint presentations. To do so, in the File menu in the menu bar, drag your pointer to the Export To option. There you can choose another format to save in, including the app’s Office equivalent.
To open an MS Office document in an iWork application, drag it onto the iWork app’s icon or Ctrl-click on the file, choose Open With and select the app you want to use.