The "Pound Shilling Penny" was a currency system used in the United Kingdom before decimalization in 1971. It consisted of three main units: the pound, which was worth 20 shillings, and each shilling was further divided into 12 pennies. This meant that one pound was equal to 240 pennies. The system was often represented using the symbols £ for pounds, s for shillings, and d for pennies. For example, 10 shillings and 6 pennies would be written as 10s 6d. The transition to a decimal system simplified currency calculations, making it easier for people to understand and use.