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
Decimal fractions. The Egyptian hieratic numerals, the Greek alphabet numerals, the Hebrew alphabet numerals, the Roman numerals, the Chinese numerals and early Indian Brahmi numerals are all non-positional decimal systems, and required large numbers of symbols. For instance, Egyptian numerals used different symbols for 10, 20, to 90, 100, 200, to 900, 1000, 2000, 3000, 4000, to 10,000. The world's earliest positional decimal system was the Chinese rod calculus. Decimal fractions were first developed and used by the Chinese in the end of 4th century BC, and then spread to the Middle East and from there to Europe. The written Chinese