Okay, so sometimes "Norden" is "the Nordic countries," sometimes it's "the Nordic region," and sometimes it's "the North." Which I understand, because it's really all of those things. But it's frustrating when you choose to translate it as, say, "the Nordic countries," and you're told that you're wrong. Especially when Duo tells you that "the Nordic region" would have been an acceptable answer.
I just don't think it makes sense to say that 'Iceland is in the Nordic countries', do you? Norden is a name in Swedish, just like Europa for 'Europe', but 'the Nordic countries' is not a name in English. It's not like Iceland is located in any other country than, well, Iceland.
the Nordic region is an accepted answer here though.
The problem is that it feels so inconsistent. If I get "Sverige ligger i Norden" as a sentence to translate, then "Sweden is in the Nordic countries" is an acceptable answer (and I don't think "Sweden is in the North" would be, though I haven't tried). I just want some consistency, is all. I don't like having to guess which answer is "acceptable" when trying to translate something that in some ways just doesn't have a good English translation.
Sure, people disagree about which countries are Scandinavian or exactly what Scandinavia is, but there's no problem with the Nordic countries. Iceland and the Faroe islands are definitely Nordic countries. There's also Nordiska rådet, the Nordic council, and various types of economic/political collaboration which makes it extra clear which countries belong in the group – for instance we were able to travel to all Nordic countries without passports even before we joined the EU, so this distinction is a lot more tangible than the idea of "Scandinavia".
OK, so, translating this as 'in the North' is technically correct but really ambiguous, especially if you're saying it and not writing it (because you can't tell that 'the North' is a proper name), and even more so since 'the North' is actually idiomatically used in some dialects of English for referring to other regions (such as the northern parts of the UK). 'among the Nordic countries' or 'one of the Nordic countries' seems like a more idiomatic English translation to me (note, 'Nordic countries' is a thing in English as an idiomatic translation of 'Norden', it's just not really used much in everyday conversation because the Nordic countries are not something most native English speakers discuss with any regularity), or possibly even 'a member of the Nordic Council' (which is even less ambiguous, but potentially changes the meaning of the sentence).
I wrote "Iceland is in Scandinavia", which was marked wrong, but seems right to me (Depending on whether or not one thinks Iceland is a part of Scandinavia. Please Scandinavia, make up your mind ;) ). I think it's an acceptable sentence in English or am I missing something?
It's not accepted, because Scandinavia and the Nordic countries are not interchangeable in a Swedish context. In Sweden, the Nordic countries are Sweden, Denmark, Finland, Norway and Iceland and their dependencies (Faroes, Greenland, Svalbard etc).
Scandinavia on the other hand, means only Sweden, Denmark and Norway.
In English, the terms are often used interchangeably though. But since we're trying to teach the differences in Swedish, we're quite picky on technicalities here.
Purely from a translation perspective, it's wrong because Scandinavia = Skandinavien.
You are correct that "Scandinavia" means different things to different people, but I think for the overwhelming majority of people from North-Germanic countries, it specifically means Norway, Sweden, and Denmark - those three countries in Northern Europe whose languages are mutually intelligible. It seems to be mostly English-speakers who try to add Iceland and Finland to the list.