Thousands separator: How do I get 12634 to display as 12,634?

Try this:

• Tap [Conv] [Prefs]
• You should now be at the Preferences screen.  Scroll down to the “Thousands Separator” cell.
• Tap the toggle switch in the “Thousands Separator” cell to turn it “ON”
• Tap the [Done] button at the bottom right of the screen
• Any new entries or results will use a thousands separator.