Please forgive my angry sub-tone if it should surface, as I have spent literally hours trying to configure Moodle 3.5 doing the very most basic task in managing grades, namely calculating a grade point between, say, 1 and 10 from the marks.
I have a quiz with a total of 7 marks whose maximum grade I can set to 10 and this seems to set the maximum grade in the grade item settings to the same. The respective field is grayed out and I have not found any way to change its value. Probably that would not make much sense either. However, the minimum value should absolutely be editable but it also is locked down to the value 0 and I have not found any way of changing it either.
In the site-wide general settings for grades there is a Boolean property "Show minimum grade" (grade_report_showmin, default = Yes) with the following short explanation: "Minimum grade is used in calculating grades and weights. If not shown, minimum grade will default to zero and cannot be edited." (<sarcasm>The explanation does not claim that the minimum grade can be edited when the minimum grade is shown.</sarcasm>)
There does not seem to be any good way of solving this problem. The only propostion I found was defining a scale with 91 steps from 1.0 to 10.0 which, frankly speaking, as absurd an approach as a desperate one.
Richard van Iwaarden raised the issue "[3.5]Minimum grade in gradebook can not be edited" here in this forum in January but has not received much feedback and the discussion thread died out end of February. Please look there for screen-shots.
My work-around is to set the multiplicator to 0.9 and the offset to 1.0 . This way the boundary value 0 or 10 get mapped to 1 or 10, respectively, with linear interpolation in between. This seems way too much hassle for such a basic task. I must mention that after the frustrating hours of uselessly poking around in the settings, I was only glad that this finally worked.
Two questions arise.: 1.) Does this have to be so complicated, or have I been overlooking anything obvious or otherwise well-known? 2.) Is the minimum value editable and effective in more recent versions of Moodle?
PS: I just stumbled over the thread "Minimum and Maximum grades of a quiz can not be changed." raised by Visvanath Ratnaweera just a few weeks ago. For reasons that I cannot understand, there does not seem to be much hope to see this behavior changed. So I let my posting stand for the case that it can give other desperate Moodle users an idea for a work-around.
Nevertheless, I would like to mention that several European countries use a grading system starting at 1 instead of 0. Germany uses an inverted scale from 6 (lowest grade) to 1 (highest grade). And I do not see any reason why a linear scaling from [0,maxMarks] to [minGrade,maxGrade] could not be easily implemented.
Nevertheless I am thankful to all the developers for making Moodle available.