1. Return to your course front page and look for Grades in the Administration block:

2. Click on Grades and you'll be taken to the Grader report page. We are now in the Moodle grade book. I'm not going to worry too much about all of the features in the grade book for the moment—but while you are there you might like to spend a little time having a look. As with anything else in Moodle, you can't do any damage by doing something by mistake.

3. At the top left of the page, you will find a list of view options:

4. From the list select Scales. You're now taken to the scales page. We need to add a new scale, so press the Add a new scale button in the center of the page.

5. On the following page, give your new scale a name and in the Scale box you can specify the possible grades contained in your new scale. Separate the grades with commas—no spaces. Make sure you specify the grades in order of increasing value:

6. You don't have to worry about a description...