Currencies around the world normally have coins/notes of values 1,
2, and 5 (with or without one or more zeros added, and some values may be skipped). Exceptions would be Canada and the US which use a 25 cent coin (rather than 20 cents), and no 2 cent coins in recent years. Are there any other (decimal) currencies that vary from the 1, 2, 5 format?
If you’ll allow currencies that are no longer in use, the UK pre-decimal system was quite different:
1 pound divided into 240 pennies (pence). 12 pence make a shilling; two shillings make a florin; 5 shillings make a crown. 1 pound and 1 shilling is a guinea.
Half a shilling is sixpence; half a crown is 2 shillings and sixpence; half a sixpence is thruppence. A penny was also divided in half (halpenny) and quarter (farthing) - going further back there were halves and thirds of farthings, and groats, which were four pence.
Japan apparently does not have the equivalent of either twenty or twenty-five cent coins.
The smallest paper note in Japanese currency is the 1,000 Yen note (equal in value to around seven US dollars). Moving up, Japan has 2000, 5000, and 10000 Yen notes so those match what the OP described.
But currently issued Japanese coins are 500 Yen (the equivalent of a half dollar), 100 Yen (a dime), 50 Yen (a nickel), and 10 Yen (a penny), along with 5 and 1 Yen coins. So even if you start from the 1 Yen coin and move up in value, there’s no equivalent of a quarter or twenty-cent piece.
And even there, the 2000 yen note is not common. I went on a trip over there, changed some money before hand, and got several of these. They were considered a bit of a curiosity and treated somewhat like $2 here (many of the cash registers I saw didn’t even have a slot for them). I gave several as wedding gifts to some friends, and they asked where I had come across so many.
The craziest coin here is indeed the guinea, amounting to a multiple of 1.05 of the base currency unit. To my knowledge, it is still somewhat in use as an accounting unit in professions where an intermediary brokers a transaction: The buyer pays the purchase price in guineas, but the seller receives the same figure in pounds, amounting, effectively, to a 5 per cent commission added on top of the price.
Jordanian coins never followed “1, 2, 5…” exactly, nor American fractions exactly:
Coins were introduced in 1949 in denominations of 1, 5, 10, 20, 50 and 100 fils. The first issue of 1 fils were mistakenly minted with the denomination given as “1 fil”. 20 fils coins were minted until 1965, with 25 fils introduced in 1968 and 1⁄4 dinar coins in 1970. The 1 fils coin was last minted in 1985. In 1996, smaller 1⁄4 dinar coins were introduced alongside 1⁄2 and 1 dinar coins.
If I understood that correctly, that leaves current coins as 0.005, 0.01, 0.025, 0.05, 0.10, 0.25, 0.50, and 1.00 dinars.
Just wanted to point out that in 1875-1878 the United States had a twenty-cent coin. It was unpopular, one reason that it was so close in size to the twenty-five cent coin.
And years later the mint put out the Susan B. Anthony dollar, which was…too close in size to the twenty-five cent coin.
You might also be interested in the “bit”, from which comes the expression “two bits”. Nothing to do with the bitcoin, it referred to the colonial practice of actually chopping up a dollar coin into eight pie-shaped wedges called bits.
I just want to point out the inconsistencies in the current USA denominations:
Coins: 25 cents, very common
Single-digit dollars: A $2 note exists, but is hardly ever used except in certain businesses.
Double-digit dollars: The $20 note is very common.
Triple-digit dollars: There’s a $100 note and a $500, but I don’t think there’s ever been anything in between