Wayne Pearson writes:

That's a very strange argument, and I'm sure I won't be alone in pointing out that "dime" owes its origins to "dixième" in French or its Latin ancestor, meaning precisely "tenth", and "cent" from "centième" or hundredth. Different languages, same terms. As for tens and hundreds being hard, why do we do math in base 10 rather than base 8 or base 16?

I can understand the historical logic of carrying over quarters of cut Spanish dollars into modern usage, and that's probably the only explanation needed for the 25c piece. A quick look around Europe shows the situation isn't so cut-and-dried. Prior to the Euro, Holland had a 25-cent piece (and Belgium 25 centimes), but East Germany 20 pfennigs, Italy 20 centesimi and France 20 centimes (though the latter also had "quarters" at various times) - and Russia did its own thing with 1, 2, 3, 5, 10, 15, 20 and 50 kopeks!

Even dollar currencies closer to the US don't all follow the US pattern - 15 and 25 cents in the Bahamas, both 20 and 25 cents in Jamaica, and the independent territories throughout the Pacific have 20s rather than quarters ... is it really anything more than just local habit?

Want a few thoughts on that 25c and $20 issue? I noticed it some time ago and was thinking of a logical reason why it might be true. The answer is, our dollar system is based on 1s, 10s, and later 100s, and other denominations are found by halving those numbers. Half of $1 is the half dollar, half of that is a quarter dollar, etc.

Here's the thing: originally, our coinage system only went to $10. We got a $20 coin in 1849 because instead of halving/quartering a $100 denomination, we doubled the $10 denomination. Paper bills came a few years later, and at that point we may as well stick with the $20 I suppose.

I am aware that earlier, private issues included $20 and $100 denominations, but those were private issues to begin with and people did all sorts of weird things back then (though often a reason was to be had). Are you familiar with the $1.67 bill (1 known) from Michigan, or the $1.56-1/4 bill (none known) from Philadelphia?

In 1988, Roger Durand published a book called Interesting Notes About Denominations, listing all the unusual denominations he found on currencies. There are no images of the bit-denominated notes, like $1.37-1/2, $1.56-1/4, $1.87-1/2, etc because none are known to survive. I mean, there are a few 18-3/4c notes of course...

Now if you go further into this, like privately-issued scrip, you get other interesting results that Durand did not note. For example, the Liverpool NY depression scrip has face values of 50c cash/52c trade and $1 cash/$1.05 trade.

If you go into tokens, you of course get even more unusual denominations, something people don't even think about if they just stick to American coins. I know in the past you've brought up the Awensdaw $1.10 token before. I know a lot about denominations because I just published my research into these in the October and November issues of Talkin' Tokens (NTCA publication).

To read the earlier E-Sylum articles, see:
PEARSON: MORE DESIGNS FOR U.S. PAPER MONEY(https://www.coinbooks.org/v24/esylum_v24n39a14.html)
WHY DO WE HAVE A $20 BILL AND A 25 CENT COIN?(https://www.coinbooks.org/v24/esylum_v24n40a12.html)