Tradition, it seems. Many European countries place the euro sign (€) after the number. One interesting theory is that it follows from British usage for the pound (£) from the pre-decimal era of pounds/shillings/pence, when amounts were written with slashes, e.g. £ 3/5/6, or “three pounds, 5 shillings, sixpence.” It was understood that £ referred to the whole assembly of numbers denoting a system of currency, not just a qualifier of the first number. Interesting side note: the word “dollar” derives from Low German “taler,” short for “Joachimstaler,” the name of a coin from the silver mines of that name, once in Bohemia, now a town in the Czech Republic; it was adopted in the US because it was the British English word for the Spanish Peso, a common currency in the colonies at the time of the Revolution. bit.ly/whence-dollar