Is there a simple way to subtract base-60 (coordinate system) values?

A trivial example:
I have a Lat of 44.1 degrees and I want to subtract 0.2 degrees from it.
 Therefore the answer should be 43.5 degrees (base 60).

I can do a change to character; stringsplit ; change back - deal with the
leading zeros but there must be an easier way.  (?)

Thanks for the help.
Trevor

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