There were
12 pence to a shilling a twenty shillings to a pound for a reason. It's just that now people are so used to the measured being made to match the measurement rather than the other way around.

We had money in that form because a thousand years ago, the worth of the metal was based on its weight, which is where "pound" comes from. Next most precious metal was silver, so how many pennies was worth a pound of gold? And so on. By 1966 the system was meaningless, so they decided that having everything in tens and hundreds would be nice and simple and so valued the currency to match.

That's my understanding of it, anyway. I have been known to talk bollocks from time to time.
( Kroney, Tue 7 Oct 2008, 18:11, Reply)