[gradebook2-dev] question about grading using letter grades

[Jim Mezzanotte]

I think the question here (apologies if I'm wrong) is how the
gradebook arrives at a calculated grade when it's set up for entering
letter grades for items. If you use the default "letter grades"
format, you get the following ranges:

A = 90 to 100
B = 80 to 89.99
C = 70 to 79.99
D = 60 to 69.99
F = 0 to 59.99

Given these ranges, how does the tool determine the points for an
entered score?  If you enter "F" for an item (assuming item has 100
max pts)--and that is the only item graded--the calculated grade is
58.333...  So the tool is determining a specific value for each range,
but it's not clear how. The midrange value for "F" would be 29.995. As
another example, the midrange value for "C" would be 74.995. Yet, if
you enter "C" for a single item, the calculated grade is 75.

I'm not sure if the tool might be rounding up. You'll also see a
discrepancy between midrange value and calculated grade with the
default "letter grade with +/-" format. For example, if you enter "B-"
for a single item, the calculated grade is 81.666....  But, the
midrange value would be 80.995.

Best,
Jim Mezzanotte
rSmart