£sd (occasionally written Lsd) is the popular name for the pre-decimal currencies once common throughout Europe, especially in the British Isles and hence in several countries of the British Empire and subsequently the Commonwealth. The abbreviation originates from the Latin currency denominations librae, solidi, and denarii.
Under this system, there were 12 pence in a shilling and 20 shillings, or 240 pence, in a pound. The penny was subdivided into 4 farthings until 31 December 1960, when they ceased to be legal tender in the UK, and until 31 July 1969 there were also halfpennies (“ha’pennies”) in circulation. The advantage of such a system was its use in mental arithmetic, as it afforded many factors and hence fractions of a pound such as tenths, eighths, sixths and even sevenths and ninths if the guinea (worth 21 shillings) was used. When dealing with items in dozens, multiplication and division are straightforward; for example, if a dozen eggs cost four shillings, then each egg was priced at fourpence.