Convert from button measure to hectometer

Unit Definition (button measure)
The button measure is a unit of distance equal to 1/40 inch (0.635 millimeter), used to measure the thickness of buttons.

Unit Definition (hectometer)
A hectometre (American spelling: hectometer, symbol: hm) is a measurement of distance equal to 100 metres. This measure is rarely used and is included mostly for completeness, since usage of the SI prefix hecto is no longer recommended.