Decimalisation or decimalization (see spelling differences) is the conversion of a system of currency or of weights and measures to units related by powers of 10.. Most countries have decimalised their currencies, converting them from non-decimal sub-units to a decimal system, with one basic currency unit and sub-units that are to a power of 10, most commonly 100 and …

Decimal Day in the United Kingdom and in Ireland was Monday 15 February 1971, the day on which each country decimalised its respective £sd currency of pounds, shillings, and pence.. Before this date in the United Kingdom, the British pound was made up of 20 shillings, each of which was made up of 12 pence, a total of 240 pence. With decimalisation, the pound kept its …