Create and Arrange Categories and Grade Items
When you add graded Moodle activities to your course, such as Assignments or Quizzes, corresponding grade items (columns) are added to the gradebook. You may also manually add columns to your gradebook for offline assignments. See Adding and Editing Categories & Grade Items. You can setup the grade categories and items as you go, or at the beginning of the course, but the organization of these categories and items is essential to calculating final grades with results you desire.
Configure Grade Calculation
Grade calculations depend on how the categories and items are arranged on the Gradebook Setup page. To learn how grades are calculated, you need to know more about Natural weighting – the aggregation method of the new gradebook. Natural Weighting
Equal weighting in subcategory
Moodle will automatically calculate grades for a subcategory using natural weighting.
You will notice that the total weight for the category Homework is 15%. Each grade item is equally weighted based on the number of assignments in that category, regardless of the points assigned per graded item. The total points for the category equals the natural addition of all point values for assignments in that category. If the weights for graded items are not overridden by selecting them, then they are simply for informational purposes, to inform the instructor what the relative weights of the items are.
Specific weighting in subcategory
Moodle will calculate grades for a subcategory using specific weighting when you select graded items and set specific weighting for each as long as the total weight is equal to 100%.
You will notice that the total weight category for Homework is still 15%. Each grade item is still worth 100 points each, yet they have been individually weighted based on instructor preference. The total points for the category still equals the natural addition of all point values for the assignments in that category.