Brits use all metric, with a couple of exceptions:
1) Distances and speeds are measured in miles and miles per hour respectively;
2) Almost all liquids [including gasoline] are sold in litres now, but you still buy pints [20 fl oz] or half-pints of beer and certain other beverages;
3) Power is generally measured in kW, though occasionally folks still use BTUs.
The Brits only decimalized their money in 1971, so that 100 pennies make up 1 pound. Prior to that, 12 pennies made up a shilling, and 20 shillings made up a pound [the system being known as pounds, shilling and pence – 240 old pennies to the old pound].
At the time of “decimalization” as it was known, some of the old coins could be used to represent the new ones, until they left circulation – e.g. the old 1 shilling coin, worth 12 old pennies became equivalent to a 5 penny piece.
The term “what’s that in old money?” has entered the British vernacular to describe a situation where someone is trying to correlate a new piece of info, to something they already know… as you can guess, it originates from the period of decimalization…
A Brit pint is 1/8 of an imperial gallon, consisting of 160 imperial ounces. A US pint is 1/8 of a US gallon, consisting of 128 Yankee ounces.
One imperial ounce is 28 ml, and one US ounce is 30 ml, so one Brit pint is 560 ml, and one US pint 480 ml. This is why Brits get so drunk at soccer matches: they are drinking 17% more beer per pint.