You use the metric system for your money, don't you?
I don't know that our money is defined by
•THE• metric system, but it is based on powers of ten.
And here's something interesting that I learned, a year or s ago.
The dollar, of course, is our basic unit of currency. We also have a unit called a cent, which is defined as 1/100 of a dollar. Look at the back of an American penny, and you'll see that it states its value as one cent. Look at a nickel, and it will state its value as five cents.
So, what does it state, as the value, on the back of a dime? Ten cents? No. It gives its value as one dime. It turns out that we also have an officially-defined unit of currency called a dime, which is defined as 1/10 of a dollar.
We have some other officially-defined units which are much less widely known or used. There is a mil, which is defined as 1/1000 of a dollar. The smallest coin ever issued was a 5-mil coin, or half a cent. Some states, at one point, issued 1-mil tokens, that could be used to pay taxes which were assessed down to the mil.
Also defined, but not widely used, are the eagle, which is ten dollars, the union, which is a hundred dollar, and the grand, which is a thousand dollars; though
“grand” is often used as a sort of a slang term, by people who mostly do not realize that it's not really slang, but a true, officially-defined unit, that means exactly what they think it means as a slang term.
This has led me to wonder about something. Motor fuel prices are nearly always specified to the mil. If I were to go to a gas station,and buy exactly a gallon of gasoline priced at 3.499/gallon, and I were to use cash or a debit/credit card to pay for my purchase, it'd be rounded to the cent. I wonder if it's possible, that if I went to a gas station that would accept a stone-age paper check, if I could write a check for exactly $3.499, thus paying the exact price of that gallon of gasoline, and if my bank account would then have its balance reduced by that exact amount, down to the mil. I wonder if internally, banks maintain balances to a finer granularity than the cent. Seems to me like they'd have to, to accurately calculate interest in some cases.