I thought I had this set correctly but apparently not.
I have set up a rubric with 7 criteria where no points can be gained - all options are 0 points. And one criteria providing the grade - this has a minimum value of 0 & a maximum value of 100
So all students would get (0 *7 + x ) / (0*7 + 100) = x/100
The statement does go on about the score being between 0 & 100:
The minimum possible score for this rubric is 0 points and it will be converted to the minimum grade available in this module (which is zero unless the scale is used). The maximum score 100 points will be converted to the maximum grade.
Intermediate scores will be converted respectively and rounded to the nearest available grade.
If a scale is used instead of a grade, the score will be converted to the scale elements as if they were consecutive integers.
However the actual grade calculated ends up being X+1 or X-1 on the grading scale used. (So if iI had values 0,10,20,40,60,80,100 in the final criterion and I picked 60 it would show up as 80 or 40 & very rarely as the correct value of 60)
According to the previous discussions, I believed this would calculate the grades correctly but it doesn't!
Makes me want to get a new Advanced Grading method developed which can calculate grades properly and reliably!!! If anyone else is interested in doing the same, get in touch !