Pre-Decimal UK currency

Before decimalisation, Britain had 12 pennies in a shilling and 20 shillings in a pound.

That means there were 240 pennies in £1.

Which sounds completely deranged when you’ve grown up with 100p in a pound.

My immediate question when I learned more about the system wasn’t even “why not 100?” It was: why not 120? You still get loads of useful divisions and you’ve immediately halved the number of tiny bits of money everyone has to deal with.

The answer sent me backwards through centuries of monetary history, into pounds as units of weight, Roman denominations, medieval accounting and the surprisingly useful property of 240 being divisible by loads of numbers.

This is the problem with asking apparently simple questions about things people did for hundreds of years.

Usually the answer isn’t “people in the past were idiots.”

It’s “this made considerably more sense at the time, and now you’re going to spend an hour learning about medieval coinage.”