German says the euros, then the cents, with nothing in between: drei Euro fünfzig = 3,50 €. And the comma sits where an English speaker expects a point — 3,50 is three euros fifty, not three thousand five hundred.

⚠6,90 and 9,60 are the same two numbers in the other order — and after Unit 2 you know German says the ones before the tens too. When it matters, ask: „Wie viel, bitte?"