Fifty years ago today, Britain and Ireland said goodbye to pounds, shillings and pence and welcomed decimal money. From 15 February 1971, there would be 100 pence in a pound, rather than 12 shillings. That changeover decimal day in Britain was billed as D Day, no doubt a deliberate echo of the the D Day landings during the war, less than 27 years before.

I’m sure the decimal revolution was a wrench for my grandmothers, who grew up with Queen Victoria’s head on the nation’s coins. For me, it was a relief: as a seven year old, it meant an end to painful school maths lessons adding up in old money. But I still feel nostalgic for that lost world.

I grew up on old money, but was aware that change was on the way. Not long before decimalisation, my great aunt Megan offered my a choice: I could have my pocket money as a 10 shilling note or a 50p piece. I had never seen a 50p piece so went for that. Looking back, it was very generous regardless of the option I went for.

Just days before Decimalisation Day, I saw a money box in a shop window in Teddington, Middlesex. It had tubes for the different British coins. I wanted to buy it. “It’s a waste of money. We’re going decimal next week, and you’ll never use it,” insisted my mother. (That wartime generation was always alert to wasting money.) The shop on Teddington’s railway bridge later became a Blockbuster Video store. When I was living in Teddington in the late 1980s I remembered my mother’s intervention every time I popped in to get a film to watch on a Saturday night. Ironically, Blockbuster and video stores have followed the shilling into history.

The switch to decimal currency was a massive operation. Ian Mansfield has written a fascinating account of how London Transport switched on his Ian Visits website. It converted double decker buses to mobile classrooms for staff training. The Underground went decimal a day early, on Sunday 14 February 1971, to avoid making the switch on the busy first day of the week. 

The retention of the pound and the penny meant ‘new money’ was not totally different, unlike the switch to the euro in Ireland and elsewhere in Europe 20 years ago. And the old florin (the 2/- or two shilling coin) and 1/- (shilling) coins remained in everyday use for over 20 years after D Day, as they were the same size as the replacement 10p and 5p coins. So even those born long after decimalisation might find a coin bearing the head of long dead monarchs such as King George V or even Queen Victoria in their change.

The much loved sixpence also survived until 1980 as a 2^1/2 pence coin. Well into the 1970s the old tradition of placing sixpences in the family Christmas pudding endured. We were less health and safety conscious in those days! The last of the old coins, the florin, were withdrawn in 1993 when the equivalent 10p coin was reduced in size.

While old money is only a memory, it lives on in our language. We still talk about turning on a sixpence, and taking the Queen’s shilling. And talking of language, we remain confused: you hear people talk of one pence rather than one penny. (Pence is a plural.)

I may have escaped years of doing sums in old money but I did get a reminder of those school lessons when I started work at Nationwide Building Society in Newport, South Wales, in 1986. In those days, building society savers had a passbook to keep track of their money, with transactions recorded line by line. Every year, they’d bring the book into the branch for interest to be added. Many savers forgot to do this, and as a cashier one morning in 1986 I was given a passbook with all its transactions in old money. I had to look up the missing interest payments on a microfiche reader, convert them to decimal money and bring the book up to date. Happily, it was my only work experience of old money, although I can convert shillings and pennies to decimal reasonably quickly even after all this time.

Decimalisation was a triumph of organisation and education – an object lesson for today’s governments in how to manage change. Will they learn?