> Before I go further I must point out that Australia, the UK and New Zealand had a much more difficult task than the US if or when it converts to Metric. Reason: our currency followed the LSD system—Pounds, Shillings and Pence—so we had the double-sized problem of converting both the currency and weights and measures.
I don’t agree with how you seem to be treating currency decimalisation as part of metrication, when to me it is a completely separate topic: the metric system is a system of units for measuring physical quantities; currencies and units of account are not physical quantities, and as such do not form any part of the metric system.
Also, some other countries who had weird-sized currency subdivisions got rid of them in a very different way: hyperinflation can quickly render currency subdivisions practically irrelevant-if a loaf of bread is a thousand pounds, nobody cares about shillings or pence any more. Of course, if you have the choice, an ordinary currency switchover is much better than hyperinflation.
All I can add is that I lived through both conversions and witnessed them from day-to-day.
They were planned by greater minds than mine to follow one another with the metric building on the momentum of the first. Outcomes are what ultimately matter, both conversions along with those in NZ have been recognized as some of the most successful of all time.
Decimalisation is different to metrication but they were not perceived that way, instead they were a political matter and that required a political solution involving Parliament, and that's an altogether different matter.
BTW, well before the French Revolution when the Franc was set in stone the French currency followed the same divisions as the UK pound, the livre was divided into 20 then 12. Similarly length, the French inch if I recall is marginally longer than the Imperial one. Again, it's politics at work here, both currency and measures are often closely aligned.
I don’t agree with how you seem to be treating currency decimalisation as part of metrication, when to me it is a completely separate topic: the metric system is a system of units for measuring physical quantities; currencies and units of account are not physical quantities, and as such do not form any part of the metric system.
Also, some other countries who had weird-sized currency subdivisions got rid of them in a very different way: hyperinflation can quickly render currency subdivisions practically irrelevant-if a loaf of bread is a thousand pounds, nobody cares about shillings or pence any more. Of course, if you have the choice, an ordinary currency switchover is much better than hyperinflation.