British pre-decimal Currency

Before decimal currency was introduced in the United Kingdom in 1971 the pound sterling  was divided as follows:

There were twenty shillings (usually written S or s, from the Latin solidus) in one pound (written £ or L, from the Latin libra),
There were twelve pence (usually written D or d from the Latin denarius)
There were 4 farthings in 1 penny. The plural of penny was normally written pence.

Coins were issued for farthing (obsolete in the 1950s) , half-penny (ha'penny), penny, three pennies (three pence), six pence (a tanner), shilling (a bob), two-shillings (also known as a florin) and two-shillings and six-pence (known as half-a-crown).

The following were conventional ways of writing money amounts:

2/6            2 shilling and 6 pence.
1/11¹/₂     1 shilling and 11 pence ha'penny. 
£3 7s 6³/₄d    3 pounds, 7 shillings and 6 pence three farthings.