Yes, the "halvfems", "half five", could be translated as "half of the fifth twenty", or even "halfway of the fifth twenty (from the full fourth one)". Luckily

Yes, the "halvfems", "half five", could be translated as "half of the fifth twenty", or even "halfway of the fifth twenty (from the full fourth one)". Luckily it is only numbers 50 to 99 that work that way. 31 is simply "enogtredive", as in "one and three tens". A hundred is "hundred", not "fems", as it could be (five twenties).