Britain adopted decimal currency in 1971.
Prior to 1971 the currency was very complicated. There were 12 pennies in a shilling and 20 shillings in a pound. This was not suitable for modern international commerce and especially computers.
Jefferson designed a decimal system for weights and measures which was proposed to Congress before the metric system (The SI system) which is now used throughout the world. He also devised a decimal system for the currency based on the Spanish dollar. The former was rejected by Congress and the US stuck to the clumsy British system, adding some further problems by redefining a gallon and so on. The US is one of a handful of countries still stuck with the Imperial system though it did adopt the decimal currency in 1792.
No. The UK refuses to adopt the Euro and refuses to accept the Euro.
United States
Australia was colonised by Great Britain. It therefore followed that, at Federation, Australia would adopt the Westminster system of government used in Britain.
On 15 February 1971, known as Decimal Day, the United Kingdom and Ireland decimalized their currencies.
Britain ,Because they have the very stong in value POUNDNote 100%
The old Australian pre-decimal currency, based on the British currency, changed over to decimal currency on the 14th of February, 1966. The old currency was subsequently withdrawn from circulation very quickly, and within as little as six months, it was quite unusual to see any examples of the old currency in circulation, although the odd coin turned up here and there for years.
Poland didn't adopt euro currency yet. Poland still uses PLN (Polish New Zloty).
They didn't want to adopt to a single currency because it would withdraw their own coins and paperbill's from circulating.
1972
THe Zloty IS the currency of Poland... and will remains so until they decide to adopt the Euro.