خمس, "fifth") is the subdivisory unit of the Mauritanian Ouguiya
. Five khoums make an ouguiya, hence one khoums can be expressed as MRO/0.2; two as 0.4, four khoums as 0.8, etc. However, due to the khoums's extremely small value (about 0.058 euro
cent as of 2006), the khoums probably fell into disuse as a unit of account quite some time ago.