Non-decimal currency Non-decimal currency A non-decimal currency is a currency that has sub-units that are a non-decimal fraction of the main unit, i.e. the number of sub-units in a main unit is not a power of 10. Today only two countries in the world use non-decimal currencies. Both of these countries are in Africa. These are Mauritania (1 ouguiya = 5 khoums) and Madagascar (1 ariary = 5 iraimbilanja). However these are only theoretically non-decimal, as in both cases the value of the main unit is so low that the sub-unit is too small to be of any practical use and coins
Coins of the pound sterling abbreviation for the old penny, d, was derived from the Roman "denarius", and the abbreviation for the shilling, s, from the Roman "solidus". The shilling was also denoted by the slash symbol, also called a solidus for this reason, which was originally an adaptation of the long s. The symbol "£", for the pound, is derived from the first letter of the Latin word for pound, "libra". A similar pre-decimal system operated in France, also based on the Roman currency, consisting of the "livre" (L), "sol" or "sou" (s) and "denier" (d). Until 1816 another similar system was used in