On rare occasions, instructors may wish to change the letter grade boundaries from the University’s standard default settings. Moodle's letter grading configuration defaults to a standard 11-part system:
Moodle uses precise calculations to the number of decimal point positions you set, but does not round up past that value (e.g., 89.99% is still a B+.) You may manually edit the highest value before the change to the next grade (e.g., change grade boundaries so that 89.59 is the highest B+ score, and 89.60% and above will be an A-).
Editing the letter grade boundaries
Go to the course homepage.
Find the Administration block:
Click Gradebook setup (Grades in Moodle 2.8).
From the gradebook drop-down menu, under the Letter Grades heading, select Edit.
Check Override site defaults box.
Choose a new Letter grade boundary value or enter different alpha letter grades.