Gradually I learned to use the pesky number keys at
the top of the keyboard
 and ignored the numeric pad completely.  Even today I ignore the numeric pads
 because they don't have comma keys on them. 
What happens when you come across the One True Keyboard (VT100)
or its descendants, which do have a comma on the keyboard like
god intended?
There's even a DEC keyboard - the LK250 - which has a comma on
the keypad and works on PC-clones.
Tim.