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 accounting, because amounts are written down and calculated using the decimal numeral system (but when another numeral system is used, such as the vigesimal system that was common among ancient Mesoamerican civilizations or the sexagesimal system used by the ancient Mesopotamians, this advantage disappears). However, decimalised currencies also have disadvantages. The principal advantage of most non-decimal currencies is that they are more easily divided, particularly by numbers such as 3 and 8, than decimal currencies. A currency with 100 minor units to the major unit is divisible neither into 3 nor into 8, and furthermore 100 may be an uncomfortably