How do I drop the lowest grade(s) from a category in Gradebook2?
If you are using a Non-weighted (or weighted) Categories gradebook, you can arrange for a number of the lowest grades in any category to be dropped from Course grade consideration.
The gradebook must use categories (weighted or non-weighted) to use the drop lowest grade functionality.
Case: Non-weighted (or weighted) categories gradebook:

The gradebook has 3 categories (Quizzes, Papers and Participation). The instructor would like to drop the lowest grade from the Quizzes Category.
Right-click the category name and select Edit this Category.

This displays the Edit Category panel on the right.
Enter the number of lowest category grades to be dropped, then click Save/Close.

This will drop the lowest grade(s) from the Course Grade calculation.