Convert from button measure to angstrom

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 (angstrom)
The Angstrom is a metric unit of length, equal to 0.1 nanometer or 10e-10 meter. Angstroms are most often used to measure the wavelength of light and are commonly used by chemists and physicists in the field of spectroscopy. One of the pioneers of spectroscopy was the Swedish physicist Anders Jon Ångström (1814-1874), after whom the unit is named.