Is it really that strange? Think about how we say it: "I make 100 euros a day." Do we literally create those hundred euros?
Every language (well, I imagine every language - I suppose I don't know for sure) is full of phrasings that seem completely bizarre to non-native speakers.
It's the other way round – numbers normally don't need "de" (=of), just like in English: mille euros - a thousand euros. Million, milliard, billion etc are exceptions that need "de" when immediately followed by a noun.