The only way that I have been able to easily make quizzes extra credit to make the percentages for the Assignment Weightings for the different Assignment Types equal to more than 100%. I have to be careful in how I group the different assignments together, as Canvas gives its total grades as a weighted average of the averages of each assignment type. So extra credit quizzes, that all provide the same amount of points to the final grade go into one assignment type. Other assignments, like an extra credit observation project, go into another assignment type, each of my exams provides a different quantity of points to the final grade, so they each have their own assignment type. The total weightings of all my assignments adds up to 138%, so I provide an additional 38% of possible points that students can pursue if they do poorly on the regular quizzes.
Finally, in the Modules, I set the exams to be in their own module and have rules that ensure that they must do the exam otherwise they can't proceed forward, where the extra credit quizzes have no such rule associated with them, hence they can choose to do it or not, thus it becomes "extra".
This discussion post is outdated and has been archived. Please use the Community question forums and official documentation for the most current and accurate information.