Pounds, shillings and pence
From Awe
Britain adopted decimal currency – 100 pennies in a pound – in 1973. Before then, our standard currency was divided according to very old principles.
The pound sterling (see pound above) consisted of 240 pennies. This is a large number for ill-educated people; and it represents a lot of cash to carry around. So the lesser unit of the shilling was used. There are 12 pence in a shilling; there are 20 shillings in a pound. The abbreviations for these were £ s d, derived from the Latin words for the Roman coins they most closely resembled: the librum ('pound'), solidus and denarius. Hence old people can still be heard saying ‘Ell-ess-dee’ when they mean 'money'. The £ was written before the number it referred to (as it is now); the s and the d were written after. So the full expression of '2 pounds, thirteen shillings and eightpence' was £2 13s 8d, though this was usually written as £2/13/8
In recent times, the pound, before it became paper only, was a gold coin; the shilling was silver, and the penny was copper. (In practice, of course, these were no longer pure. By the twentieth century the gold in a coin was worth far more than its face value, and alloys were used for both silver and copper.)
Other coins in use at various times in history (and therefore referred to in older texts) include, in gold: the sovereign (£1) and the half sovereign (10 shillings; replaced by a note) which survived into recent times; and the noble (13/4, or 2/3 of a pound) and mark (6/8, or 1/3 of a pound), which ceased to be current coin in the Stuart period (seventeenth century). There was also the guinea (coin), which was issued between 1663 and 1813: the word is still used a a unit of price. In silver there were, among others, the crown (5/-, 5 shillings or ¼ of a pound), half-crown (2/6) and florin (2/-) among larger denominations, and the sixpence (6d, sixpence or half a shilling, slang name a ‘tanner’) and threepence (3d, or ¼ shilling, often called a ‘threepenny bit’). In earlier times there were also (among others) a groat, or 4d (fourpence), and an angel whose value varied: at different times it was 6/8 and 10/-. The shilling was often called a ‘bob’. Copper coins included the penny, halfpenny and farthing, or ¼ penny.
See also Penny - pence - pennies for subtleties involving the singular and plural of this word, and pound for the potential confusion with the unit of weight.

