How do I save the Numbers document I'm working on? Using Numbers 3.6.2, and would like to save document to finish later. Where do I save it? (Saving to PDF is permanent)
You can save it anywhere you want.  Just do Command-S or go to File --&gt; Save and it will bring up a dialog box.  You can use the default location or any other folder/location you want.

You can even save it to your iCloud account from the same dialog.  See the image below.