Moodle's Natural aggregation method takes the sum of all grade items with an optional scaling by weight. Natural is the most flexible aggregation method for your Moodle gradebook because it supports sum of points, weighted grades and extra credit.

About the Weight Column

Note: If your grading plan does not incorporate percentages of certain grade items (i.e. you intend to use only points to reflect relative importance toward the overall grade), you can ignore the weight column entirely. Only when managing the percentages of specific grade items regardless of their points do instructors need to consider the weight column.

Although you will see lots of numbers in this column, note that by default they reflect the proportion each grade item contributes to the overall course or category total based on their points. The weights of items within each category must always equal 100.

Gradebook Setup

1. In the "Setup" tab of your course Gradebook, set “Natural” as the aggregation for the top-level (course) grade category. Natural is our default aggregation method for all new courses, but courses copied over from previous years may inherit other settings. How to modify grade category settings.
   
   

2. Create grade categories for each group of activities. Common example categories are 'forums', 'assignments', 'quizzes', etc. Set these categories with the aggregation “Natural” (default). The total points for each category will be determined by the points of the items that are placed in that category.
   
   Note: If you have stand-alone assessment items, you do not need to have a category for them, but these items must be created before Step 3 can be done successfully. If you are not ready to build/design these assessment items, create a category for them instead (recommended) and add the assessment item to this category later.

3. (Optional) If using points-based assessment without weights, skip this step.
   Assign the weight for each category as described in your syllabus. In the "Setup" tab, check the checkbox next to each category to enable setting the weights value. Entered weight values for all items 1-step below the main course category must total 100. If the sum of all weights do not equal 100, Moodle will scale them accordingly to be so. Items within grade categories do not need to be assigned a weight. Their points account for their relative value in the course.
   
   
4. Create your grade items by adding an activity (like a Moodle Assignment, Forum, Quiz, or Attendance activity) on your course main page (recommended) or with the "Add grade item" in the Setup -> “Categories and items” tab of the gradebook. Place all items in their respective categories. Moving items in the gradebook.
   Tip #1: You can also define which category an activity is placed in using the settings of the activity under the Grade section.
   Tip #2: Duplicate recurring items in your course to save time building multiple items.

See https://docs.moodle.org/31/en/Natural_weighting to learn more information about Natural aggregation.