Halfpenny (British decimal coin) Halfpenny (British decimal coin) The British decimal halfpenny (p) coin was introduced in February 1971, at the time of decimalisation, and was worth one two-hundredth of a pound sterling. It was ignored in banking transactions, which were carried out in units of 1p. The decimal halfpenny had the same value as 1.2 pre-decimal pence, and was introduced to enable the prices of some low-value items to be more accurately translated to the new decimal currency. The possibility of setting prices including an odd half penny also made it more practical to retain the pre-decimal sixpence in circulation (with a value
Densely packed decimal ignored when decoding DPD groups with three large digits (marked as "x" in the last row of the table above), but are filled with zeros when encoding. The eight decimal values whose digits are all 8s or 9s have four codings each. The bits marked x in the table above are ignored on input, but will always be 0 in computed results. This table shows some representative decimal numbers and their encodings in BCD, Chen–Ho, and densely packed decimal (DPD): Densely packed decimal Densely packed decimal (DPD) is an efficient method for binary encoding decimal digits. The traditional system of