You can give extra credit in two ways. One is to allow bonus points within a particular assessment or assignment. For example, let's say you want to give students extra points for answering a bonus question in a quiz. You can decide whether the quiz grade could exceed the Out of: or Points: grade (e.g., could a student earn 110 percent?). If the quiz is in a category, you can choose whether to allow the category grade to exceed the total points for the category.
A second way to give extra credit is to create a stand-alone bonus item using the Numeric, Checkbox, or Selectbox grade item type. When you create a bonus item, the Out of or Points grade for that item will display as "0." However, any credit earned on this item will be added to the category and/or final grade. If the bonus item is in a category, you decide whether to allow the category grade to exceed the total points for that category.