Decimal Day remain unchanged. Under the new system, the pound was retained but was divided into 100 new pence, denoted by the symbol "p". New coinage was issued alongside the old coins. The 5p and 10p coins were introduced in April 1968 and were the same size, composition, and value as the shilling and two shillings coins in circulation with them. In October 1969 the 50p coin was introduced, with the 10s note withdrawn on 20 November 1970. This reduced the number of new coins that had to be introduced on Decimal Day and meant that the public was already familiar with
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