Halfpenny (Irish decimal coin) Halfpenny (Irish decimal coin) The decimal halfpenny (p) () coin was the smallest denomination of the Irish pound. It was first issued when the Irish currency was decimalised on Decimal Day, 15 February 1971. It was one of three new designs introduced all in bronze and featuring ornamental birds on the reverse. The coin value was weakened by inflation and very few were produced beyond the initial run for 1971. It was removed from circulation and demonetised on 1 January 1987. The main reason that halfpennies were issued was that when shillings were decimalised they were worth five new pence,
Decimal representation result follows from dividing all sides by formula_11. Some real numbers formula_13 have two infinite decimal representations. For example, the number 1 may be equally represented by 1.000... as by 0.999... (where the infinite sequences of trailing 0's or 9's, respectively, are represented by "..."). Conventionally, the decimal representation without trailing 9's is preferred. Moreover, in the "standard decimal representation" of formula_13, an infinite sequence of trailing 0's appearing after the decimal point is omitted, along with the decimal point itself, if formula_13 is an integer. Certain procedures for constructing the decimal expansion of formula_13 will avoid the problem of