Decimal Day and 10p coin equivalents, co-existed in circulation as valid currency until the early 1990s. In theory this included coins dating back to 1816; in practice the oldest were dated 1947, when these coins stopped containing silver. The coins were withdrawn when smaller 5p and 10p coins were introduced in 1990 and 1992 respectively. The face value of Maundy money coins was maintained, increasing all their face values by a factor of 2.4, as the coins continued to be legal tender as new pence. The numismatic value of each coin, though, greatly exceeds face value. The decimal halfpenny (p), introduced in
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),