Convert from hectometer to palm [US, Roman major]

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.

Unit Definition (palm [US, Roman major])
A palm, when used as a unit of length, is usually four digits or three inches, i.e. 7.62 cm (for the international inch). The width of an adult human male palm is indeed about 10 centimetres.In English this unit has mostly fallen out of use, as do others based on the human arm: digit (¼ palm), finger (7/24 palm), hand (4/3 palms), shaftment (2 palms), span (3 palms), cubit (6 palms) and ell (15 palms).