Chapter 38. Currency Units and Near Money
National currency systems have a base unit which may or may not be divided into subunits. Today, these subunits are usually in the ratio 1 base unit = 100 subunits or = 1000 subunits.
The only nondecimal currencies are Mauritania (1 ouguiya = 5 khoums) and Madagascar (1 ariary = 5 iraimbilanja). In both cases, the base unit has so little value that the subunit is not used, even in coins. As of June 12, 2009, the exchange rate was 1 U.S. dollar (USD) = 259.220 Mauritanian Ouguiya (MRO) and 1,895.90 Malagasy Ariary (MGA).
We like decimalized currencies because we use a decimal number system and accounting is much easier than handling fractions in a computer. But decimal currency is actually a “recent” invention. ...