Coins of the Indian rupee 3, 5, 10, 20, 25, 50 (naya) paisa and one rupee. Since rupees retained their pre-decimal value, pre-decimal coins of one, half and quarter rupees remained in circulation after decimalisation. The word "naya" was dropped in 1964 and a new denomination, the 3 paisa, was introduced into circulation. A 20 paisa coin was minted in 1968. Neither of these coins gained much popularity. The 1, 2 and 3 paisa coins were phased out gradually in the 1970s. In 1982, a new 2 rupee coin was introduced experimentally to replace 2 rupee notes. The 2 rupee coin was not minted again
Decimal and, only the best mathematicians were able to multiply or divide large numbers. These difficulties were completely solved with the introduction of the Hindu–Arabic numeral system for representing integers. This system has been extended to represent some non-integer numbers, called "decimal fractions" or "decimal numbers" for forming the "decimal numeral system". For writing numbers, the decimal system uses ten decimal digits, a decimal mark, and, for negative numbers, a minus sign "−". The decimal digits are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; the decimal separator is the dot "" in many countries (including English speaking ones),