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
Non-decimal currency said to have become the first decimalized currency when Peter the Great established the ratio 1 ruble = 100 kopecks in 1701. The Japanese were in some sense earlier calculating with the silver momme and its decimal subunits - but then the momme was not a coin but a unit of weight equivalent to 3.75 g: accounting was by weight of silver. The British pound sterling was the last major currency to be decimalized, on 15 February 1971. The Maltese waited just one year (1972) before following suit and Nigeria followed in 1973. An early proposal for decimalizing the pound