Money, since it is the lifeblood of economy and politics, sheds light on the Grand Plan of our would-be masters. Part of that plan is to persuade us that systems that worked perfectly well for centuries are somehow silly and quaint, not at all modern. Actually, the old systems often worked much better, and have been made irrelevant only by destructive changes wrought by small but well-coordinated cadres of political activists. This is as true of common law, natural justice, Magna Carta etc as it is of the allegedly silly duodecimal system.
The exchange below is part of a comment thread from the redoubtable Angels in Marble blog, which recently featured a post about the horrors of school dinners:
NOMAD: My memories of school dinners in the 40s and 50s are quite positive and all in all good value for about 1/3d. We all got fed adequately - and even on occasion there was enough left over for seconds...
HATFIELD GIRL: 1/3d, Nomad? You'll be recalling dividing £67/13/6d by £14/11/5d next. (no writing down, of course).
ROLF: "dividing £67/13/6d by £14/11/5d"= 4, remainder £9/7/10d, I think (not writing down, as you said).Now I teach children who still can't grasp multiplying by 10. The easier you make it, the dafter they get.
£14/11/5d is 8/7d short of £15.
4 x £15 = £60.
So the remainder is (£67/13/6d - £60) + (4 x 8/7d).
= £7/13/6 + 32s + 28d
= £7/13/6 + 32s + 2/4d
=£7/13/6 + 34s + 4d
=£7 + 13s + 6d + 34s + 4d
=£7 + 47s + 10d
=£9 + 7s + 10d, or £9/7/10d.
We NEVER had to do something like that, and as I say, children who can't divide by 12 also can't divide by 10.
The duodecimal system is very good for dividing sums of money by time periods or groups of people, and was appropriate when people were paid in pennies per day or shillings per week.
The x12 and x20 system is not responsible for the rip-roaring inflation of the 20th century that has systematically robbed savers and now pretty much bankrupted the nation (except for a fantastically rich and corrupt elite).
I would also point out that there are 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day - because government hasn't yet found a way to inflate time.
There are also 360 degrees in a circle, still used for navigation the world over.
If ever we do for the pound what France did for the franc in January 1960 (100 old = 1 new), the duodecimal system may come into its own again.
The rule of 10 is just part of the great plan to erase the past and all links to it, so that we may have Year Zero and the socialist millennium.