Coins of the pound sterling coins' designs. As of 31 March 2016, there were an estimated 30.14 billion coins circulating in the United Kingdom. The first decimal coins were circulated in 1968. These were the five pence (5p) and ten pence (10p), and had values of one shilling (1/-) and two shillings (2/-), respectively, under the pre-decimal £sd system. The decimal coins are minted in copper-plated steel (previously bronze), nickel-plated steel, cupronickel and nickel-brass. The two-pound coins, and, as from 28 March 2017 the new one-pound coins, are bimetallic. The coins are discs, except for the twenty pence and fifty pence pieces, both of which
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