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
Halfpenny (Irish pre-decimal coin) Halfpenny (Irish pre-decimal coin) The halfpenny (d) () coin was the second smallest denomination of the pre-decimal Irish pound, worth of a pound or of a shilling. First issued in 1928 it ceased to be legal tender on 1 August 1969. The coin measured in diameter and weighed 5.66990 grams. The bronze coin was made up of 95.5% copper, 3% tin and 1.5% zinc. This was identical to the British halfpenny as both countries' pounds were pegged until 1979. The reverse design was by Percy Metcalfe, an English artist. The artist was given the choice of a boar, a sow