@qnguyen , it sounds like you're trying to manipulate the grading scheme to account for extra credit. You might be interested in trying the solution I wrote about in Extra credit using weighted assignment groups. Let us know if this works for your intended use case!
@qnguyen ,
We are giving the Canvas Admins area a little bit of love (especially questions that are really, really old) and just want to check in with you. This will also bring this question new attention.
Were you able to find an answer to your question? I am going to go ahead and mark this question as answered because there hasn't been any more activity in a while so I assume that you have the information that you need. If you still have a question about this or if you have information that you would like to share with the community, by all means, please do come back and leave a comment. Also, if this question has been answered by one of the previous replies, please feel free to mark that answer as correct.
Robbie