Anfänger - Hilfe bei Formular mit Feldberechnungen

First step is to give your fields better names. "1" is not a good name for a field. Call it "Score1" or something like that.

Then apply each value as the export value of the radio-buttons. However, you must use the English notation, so "0.5" instead of "0,5", etc.

Once you've done all of that just go to the Calculate tab of your text fields, select the Sum option and pick "Score1" (or whatever you called it) from the list. You can set the field's Format to display the value in the German format, of course.

I've done it for you in the first group. See attached.