I have users who need to switch between Inch and Metric. They may switch back and forth in a session, depending on the customer desired format

When they want to switch to Inches the VBA code uses

        Range("B3:C8,B13:C18,B23:C28").Select  '  on sheet Dimensions
        Selection.NumberFormat = "# ??/??"

When switching to Metric

        Range("B3:C8,B13:C18,B23:C28").Select  '  Last Run/Defaults
        Selection.NumberFormat = "#0.00"

Again they may switch back to Inches, etc

The problem is the display as shown below for Inches, which is expected to the nearest 1/16

 2 1/2  should be displayed, but 2 8/16 is shown (the 8/16 looks stupid due to the "# ??/?? setting)

 2 3/4  should be displayed, but 2 12/16 is shown  (12/16 looks dumb as well, again the # ??/?? setting)

 How do I allow "to the nearest 1/16" get have it display a user friendly equivalent

Remember, users need to be able to switch back and forth between the unit systems!