Christopher Ironside coins of the British Commonwealth had their reverse designed by Christopher Ironside. These coins were struck as (Board 1): Under the provision of the Manx Decimal Currency Act of 1970, a decimal series of coins for the Isle of Man were prepared and released on 20 October 1971 (½, 1, 2, 5, 10 and 50 new pence coins). The reverse of most of these coins was designed by Christopher Ironside. This set had the same composition and size as the corresponding British coins. These coins were struck as: 1971 first decimal set (issued from 1971 to 1974): As a country
Cocker's Decimal Arithmetick Cocker's Decimal Arithmetick Cocker's Decimal Arithmetick is a grammar school mathematics textbook written by Edward Cocker (1631–1676) and published posthumously by John Hawkins in 1684. "Decimal Arithmetick" along with companion volume, "Cocker's Arithmetick" published in 1677, were used in schools in the United Kingdom for more than 150 years. The concept of decimal fractions and the advantages of using them in calculations were well known, but a wide variety of different notations were in use. After surveying various notations, "Decimal Arithmetick" recommends the decimal point notation introduced by John Napier: "Decimal Arithmetick" gives instructions for calculations involving decimals, methods of