Twenty pence (British coin) Gardner, and used from 1982 to 2008, is a crowned Tudor rose, with the numeral "20" below the rose, and above the rose. To date, three different obverses have been used. On coins minted before the 2008 redesign, the inscription is . Coins minted after the 2008 redesign also have the year of minting on the obverse. Like all the new decimal coins introduced in 1971, 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
Decimal decimal fractions were non-positional. However, counting rod fractions were positional. Qin Jiushao in his book Mathematical Treatise in Nine Sections (1247) denoted 0.96644 by J. Lennart Berggren notes that positional decimal fractions appear for the first time in a book by the Arab mathematician Abu'l-Hasan al-Uqlidisi written in the 10th century. The Jewish mathematician Immanuel Bonfils used decimal fractions around 1350, anticipating Simon Stevin, but did not develop any notation to represent them. The Persian mathematician Jamshīd al-Kāshī claimed to have discovered decimal fractions himself in the 15th century. Al Khwarizmi introduced fraction to Islamic countries in the early 9th