Coins of the Indian rupee in 1964, which was a new denomination, and continued to be minted till 1971. One and Two paisa coins were changed to Aluminium and were minted without the Devanagari legend from 1965. 20 paisa coin was introduced in 1968, which continued to be minted till 1971. From 1982, New series was launched. the 20 paisa coin which was last minted in 1971, was reintroduced again, but in Aluminium. The size and the design of 10 paisa, 50 paisa and 1 rupee was changed, though they continued to be minted in the same metal. Coins of 3p, 2p and 1p were
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