Here’s a lick and a promise converter to manage pre-decimal currency while I dust off the proper things, which I did some years ago but lost track of.
Four farthings = one penny (d, short for denarius)
12 pennies = one shilling (s, short for shilling)
20 shillings = one pound (£ or l, short for librum)
Small change
Twopence (pronounced “tuppence” 2d
Threepence (pronounced “thruppence” 3d
Groat = 4d
Sixpence = 6d
Florin = 2s
Half a crown =2/6d