Random fact: the reason an Australian dollar has long been worth approx. half a British pound is decimalisation. In both currencies before that, there were 20 shillings to a pound. When Britain decimalised, they decided that one old pound = one new pound. Australia, on the other hand, went with one old shilling = 10 cents, so the new dollar was only worth 10 shillings. Since both currencies started floating the exchange rate has bounced around a lot – AUD$1 has been worth everything from 34p in 1998 to 72p in 1984 – but the rate’s still around $1 = 56p today (or conversely, £1 = $1.78).