The ouguiya (sign: UM; Arabic:أوقية‎; currency code: MRO), also spelt "ougiya", is the currency of Mauritania. It is one of two circulating currencies, along with the Malagasy ariary, whose division units are not based on a power of ten, each ouguiya comprising five khoums (singular and plural in English, Arabic:خمس‎, meaning "one fifth").