History of the threepence the possible advent of a decimal currency at the time (see florin), when the 3d at 1/80th of a pound would not have fitted within a decimal system). Currency silver threepences from 1838 to 1926 were of identical design and cannot usually be distinguished except in the best conditions when the higher striking standard of the maundy coins stand out; this resulted in the curious legal anomaly that when the currency was decimalised in 1971 "all" silver threepences from 1870 onwards were revalued at three new pence, not just the maundy coins. Threepences were produced with both the "young head"
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