Two pence (British decimal coin) dots, a common feature on coins, known as beading. As with all new decimal currency, until 1984 the portrait of Queen Elizabeth II by Arnold Machin appeared on the obverse, in which the Queen wears the 'Girls of Great Britain and Ireland' Tiara. Between 1985 and 1997 the portrait by Raphael Maklouf was used, in which the Queen wears the George IV State Diadem. In 1992 the metal used in minting this coin was switched from bronze to copper-plated steel. From 1998 to 2015 the portrait by Ian Rank-Broadley was used, again featuring the tiara, with a signature-mark below the
Decimal separator In the Middle Ages, before printing, a bar ( ¯ ) over the units digit was used to separate the integral part of a number from its fractional part, e.g. 995 (meaning, 99.95 in decimal point format). This practice derived from the decimal system used in Indian mathematics and was popularized by the Persian mathematician Al-Khwarizmi, when Latin translation of his work on the Indian numerals introduced the decimal positional number system to the Western world. His "Compendious Book on Calculation by Completion and Balancing" presented the first systematic solution of linear and quadratic equations in Arabic. A similar notation