Years ago I was on a course to learn how to use a radio for flying. One of the airfields we had to navigate to and from was called Halfpenny Green. It's a real airfield, and is just a bit South of Birmingham in the West Midlands.
Anyway, we had to simulate the radio calls we'd make as we approached each airfield, and I was surprised when one young bloke called the place 'Half-penny Green!' I've always known it as 'Haypny Green' as that is how we've always pronounced the word halfpenny. Just goes to show how things have changed for the younger generations since we decimalised on Feb 15th, 1971, back when I was still a stripling youngster at a mere 20 years of age.
I'll bet they've never understood the old Tommy Steel musical 'Half a Sixpence' either. And as for tanners and groats, well.....!
Back in the day it was common for cinema usherettes to say things like, "This way to the one and nines!" meaning one shilling and nine penny seats. Or for ladies to buy a new set of stockings at "two and eleven" meaning two shillings and eleven pence. I can also remember that Guineas (£1 1s or twenty one shillings) were still in use for a long time even after we decimalised.