Blackboard allows you to weight grades by category or by column; it's most common to weight by category. For example, Projects = 20%, Assignments = 30%, Tests = 30% and Participation = 20% of the total grade. Blackboard will calculate the weight for each broad category no matter how many grades are in each.
Weighting by category is a three step process:
1. Set up the grade categories.
2. Apply the categories to the grade center columns.
3. Modify the Weighted Total column to reflect the categories and the percentage of the grade for each category.
This video demonstrates how to weight grades:
The attachment below describes the full process.