The UK's pre-decimal coinage system was very odd, many would say bizarre, and it's a mystery to anyone not born in Britain, or to those who were born in the last 30-plus years since decimal currency was introduced in 1971. The last of these old coins were minted in 1967, except for the farthing which stopped being made in 1956.
The old coinage was as follows: Farthing
This was the smallest unit of the old currency. A farthing being a quarter of a penny.
Halfpenny (or ½d)
The halfpenny [pronounced hay’pnee] as the name suggests was worth half a penny [and therefore two farthings].
Penny (or 1d)
The penny was much more valuable than the modern penny, and was the basic unit of currency. There were 240 Pennies to a pre-decimal pound.
Threepence (or 3d)
The three pence, or [thruppence] was worth three pennies.
Sixpence (or tanner)
The sixpence was worth six pennies.
Shilling (or 1/- or a bob)
The shilling was worth twelve pennies. There were 20 in the pre-decimal pound. The shilling was replaced by the five new pence which is 1/20 of a decimal pound.
Florin (or Two Shillings, 2/-)
The Florin was worth 24 pre-decimal pence or two shillings, and was worth a tenth of a pre-decimal pound.
Half Crown
The Half Crown was worth 30 pre-decimal pence (or two shillings and six pence, which was said as ‘two and six’). There were eight Half Crowns in a pound.
Crown
A Crown was worth 60 pre-decimal pence or a quarter of a pound. Generally, Crowns were only issued for special occasions such as the sovereign’s special anniversaries, and other state events.
Half Sovereign
Half Sovereigns had a value of 10 Shillings [ten bob].
Sovereign
Sovereigns had a face value of 20 Shillings (or a pound). As sovereigns and half sovereigns were made of 22ct Gold, they had a much higher value than their nominal value and tended not to be used as currency.
So, there it is, a strange currency which posed a problem for foreigners to understand, and complicated the mental arithmetic necessary to work out change, which had to be done as there were no computers or automatic tills way back then.
So to sum up:
1 Farthing x 2 = 1 halfpenny x 2 = 1 penny x 3 = 1 threepence x 2 = 1 sixpence x 2 = 1 shilling x 2 = 1 florin x 10 = 1 pound or £1.
Crowns, sovereigns and half sovereigns were rarely seen, most people used farthings, halfpennies, pennies, threepences, sixpences, shillings and florins, then the pound, which was paper money, as also was the ten shilling, or ten bob note, much more common than the half sovereign coin.
