Each currency typically has one fraction currency, often valued at 1/100 of the main currency: 100 centss = 1 dollar, 100 centimes = 1 franc. Units of 1/10 or 1/1000 are also common, but some currencies do not have any smaller units. Mauritania is the only remaining country that does not use the decimal system; the only smaller currency unit is the khoum, which equals 1/5 of a ouguiya (UM).