Correct.

• Half to the second (halvanden, still in use today) = 1.5
• Half to the third (halvtredje) = 2.5
• Half to the fourth (halvfjerde) = 3.5
• Half to the fifth (halvfemte) = 4.5

And so on. You might notice that I sometimes write it like “halvfemte” and other times “halvfems”. The latter is just the way it was spelled when used in a combined word (another fun quirk in Danish that we inherited from Germanic this time!). 90 is today spelled just “halvfems”.