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
£sd abandoned the £sd system quickly, while others retained it almost as long as the UK itself. Australia, for example, only changed to using a decimal currency on 14 February 1966. Still others, notably Ireland, decimalised only when the UK did. The UK abandoned the old penny on Decimal Day, 15 February 1971, when one pound sterling became divided into 100 new pence. This was a change from the system used in the earlier wave of decimalisations in Australia, New Zealand, Rhodesia and South Africa, in which the pound was replaced with a new major currency called either the "dollar" or