You can edit letter grades via the edit letters in the gradebook dropdown menu, however your edits will apply for the whole course if letter grades are used elsewhere (see Grade letters for more details). You can then change the grade display type for your quiz to 'Letter'.
I see what you're getting at Mark (hi ) but I just want a simple way of the quiz scores showing up as levels in the gradebook so teachers don't have to work out the levels from percentages. I thought editing letter grades as Helen said was the way - but I can't find where to change it in the quiz.
Just wait now - as soon as I have typed this I will find my own solution - always happens!
I currently use a custom scale in an off line assignment, extended to 1c......9a.. Put the percentage in the comments and the Grade in as a level. I then put a grid of percentages and levels in the text area (a scanned gif image file) of the Assignment. Kids then see there percentage the grade boundries and levels in grade book. (The levels can then be averaged provided they all use the same scale)
Oh the scale seems to be stored as a numerical percentage, so the bottom level=0%, top level=100%
I allso have a GCSE scale extended to 11 items of U** to A**. this means a 50% =D, 60%=C, 70%=B, 80%=A and 90%=A*. I concluded if a kid got over 99% they deserve A** in the hot potatoes quiz I use to mark multichoice exam papers papers.
It is going down great with the management since pupils are starting to compete to get high scores.
Since I mark and Grade tests internally I level them and put in the Scale letter as above. Seems to work ok for the moment.