Your comment made me realize that most unit notation I'm familiar with has the unit as a suffix, with currency being the only standout that comes to mind.
It depends on the currency / country, too. Lots of countries put the currency afterwards, even "¢" comes after. $ and £ come before, but € ends up moving depending on the language.
Binary, ocatal and hexidecimal literals often are indicated with prefixes: 0b, 0 and 0x respectively. There are probably other esoteric cases that I can't think of off the top of my head. "Qty" is often prefixed, for instance. It's a complicated problem for a natural language calculator, to be sure. Here are a couple examples of ways to represent four thousand Canadian dollars that you might encounter and have no trouble interpreting as a human. This could be a good target for an ML tokenizer...
https://en.wikipedia.org/wiki/Language_and_the_euro#Written_...