Whether it’s typed on commentary online or scrawled onto farmer stand signs, 10 US$ and US$ 10 are both widely used in the English-speaking world. The question is: which one is correct? By looking at the context of how it’s used, this question can be easily answered.
Stating a Price
When using a dollar sign to state a price by its number, the correct usage would be $10 – not 10$. Although we say “ten dollars” in that order, the unit symbol marking the 10 will precede the number. This is different than something like “ten cents”, where the cents symbol follows the number 10. This trend can be seen across several kinds of currencies, including the Euro.
Stating a Currency with a Price
The one exception to the price rule of thumb would be if someone is listing a currency. For example, stating that something costs “ten US dollars” would actually translate as 10 USD – perhaps 10 US$, if the dollar sign is used to replace the word “dollars”. In this case, there would be no exception for cents or smaller units – all statements made in currency are measured by the dollar figure. This is the same across all kinds of currencies. For example, the Japanese Yen, the European Union’s Euro, and the Mexican Peso are all the larger dollar units used to describe currencies and exchange rates.