Yeah that's the most forgivable part ;). I never understood this particular idiosyncrasy - after all you don't say "it costs dollars three", and you also put other units of measure after the value, e.g. 80 mph, 100 °F, so why on earth does the dollar sign have to go before the amount?
It makes it harder to modify amounts on checks and accounting entries. 100.00$ could more easily be turned into 1100.00$ than $100.00. It comes from a time when we did still write a lot of amounts by hand.
Except that for checks, it's not the numerical part written in the little box that matters, it's the full written amount e.g. 'Five Thousand Three Hundred Fourty-Seven and 33/100' for 5,347.33.
Similar rationale, though, because it's easier to modify a number (say, change a 7 to a 9) than to change a full word.
Wow, you're right! It's crazy how you can go your whole life never noticing or thinking about something like this that is so clearly irregular, just because it's the way you've always seen it or thought about it.
I thought for a few minutes about the reason that units of currency are different and come before the number, determined there must be an obvious logical one. But, if there is, I can't think of it!
I think it’s so you can fit the cents symbol at the end e.g. $6.75c - but this isn’t really used anymore so the dollar sign at the front is a bit of a historical anomaly at this point.
Honest question, was it ever used in that combination? I've seen ¢ used for amounts less than a dollar, e.g.: 75¢. I (still) sometimes use it like that, because, I guess, it makes me feel adjusted to my environment, as an ESL :-) But I've never seen both $ and ¢ in the same amount/expression.
Ah, so I also don't think I have seen this in practice, but I suppose it's possible that it originated from pre-decimal-system currencies, like the old British money system, where perhaps it was more important to use separate units for clarity.
I suppose it's also possible it needs to sometimes be used (although, again, I have never seen this) in certain cases in more 'formal' situations - accounting, contracts and so on. I guess the format, with the symbols wrapping the numbers so as to make them easier to parse, does make sense.
The only exception I could think of was R-values, eg, "Vacuum insulated panels have the highest R-value, approximately R-45 (in U.S. units) per inch; aerogel has the next highest R-value (about R-10 to R-30 per inch), followed by polyurethane (PUR) and phenolic foam insulations with R-7 per inch." , quoting https://en.wikipedia.org/wiki/R-value_(insulation)#Example_v... .
From the same source, "an R-value expressed in I-P (inch-pound) units[13] is about 5.68 times larger than when expressed in SI units"; the latter being measured in K⋅m2/W.
