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 The coins were withdrawn when smaller 5p and 10p coins were introduced in 1990 and 1992 respectively.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
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