I give 3 to 4 chances at doing extra credit per quarter in science. I give it as an assignment and it is the student’s choice whether they do it or not. To receive the credit, they must pass the paper with at least a 60%. I will check it just like I do for any other assignments. Their name must be on the paper. I don’t look for the owner because this is a bonus assignment and they need to put their best effort toward it.