I disagree. I don't mind the sentence here, because it seems to accept the "eight or eighty" answer (not sure if that is new). So, even if it doesn't make sense, a literal translation still works.
On a side note, it might be nice if on expressions like this, there was an extra note explaining what it means locally. Just a little extra idiomatic help.
It accepted my literal translation. And then I immediately went to the comments to find out what it meant. I love duolingo, because I think of the comments as part of the course. It doesn't bother me that I learn from the comments as much as I learn from the lesson itself.
The problem here is that since it is a Brazilian expression that means "all or nothing", it should accept both the literal translation (8 or 80) as well as the real meaning of the sentence.
O problema aqui é que uma vez que é uma expressão brasileira que significa "tudo ou nada", deveria aceitar tanto a tradução literal quanto o significado real da frase.
The reason it made it into the lessons is because somebody has translated a document literally and then a bunch of other people all voted saying it looks correct. A correct translation must satisfy the meaning of the speaker/author and unfortunately a literal translation fails to acheive that condition.