It lists "Daniel are patruzeci și șase curele." as a correct solution but surely it's wrong because it's missing the "de" after the number?
That's wrong, report it.
Why it accepts my answer without "de"? And how do I report it? There is no option to say - "My answer should not be accepted"
Is it, though? I've heard it said without the "de" before.
There might be people who leave it out, but it's not correct as in dictated by prescriptive authorities of Romanian. There are though some cases in which it is omitted, most notably on our money:
2019-04-17 It seems every country but the U.S. has such colorful currency. I'm jealous. Beautiful image, thank you for sharing! Have a Lingot.