Extra credit behaves differently in Moodle depending on the grade aggregation.
- Mean of grades (with extra credits): A value of 0 does nothing. Any other value is used to multiply the grade and add it to the total after the computation of the mean. This grade is not used in the computation of the mean, however, only added afterwards. Additionally, this cannot bring the category total over its maximum grade unless grades over 100% are enabled by the site administrator (since 1.9.5). This grade item is not counted either in the denominator used to compute the category mean.
- Natural: Extra credit is a checkbox, not a number. Normally, with Natural, the category's maximum grade is the sum of the maximum grades of all its grade items. If one of them is set as "Extra Credit", however, its maximum grade is not added to the category's maximum grade, but its grades will be. This way it is possible to achieve maximum grade (or grades over maximum if enabled by the site administrator) in the category without getting the maximum grade in all the grade items.
- Simple weighted mean of grades: Extra credit is a checkbox, not a number. The "Extra Credit" grades are counted in the numerator used to compute the category mean, but not the denominator. See here for more information.
For the purposes of this guide, we will assume the aggregation method is Simple weighted mean of grades.
Step 1:
In Grade book Setup, click Edit>Edit Settings.
Step 2:
Under the Parent Category section check Extra Credit and select Save Changes.
Step 3:
The Extra Credit assignment is indicated in Gradebook with a (+-) next to the Max Grade.
