How do I set the grade total in the exams so that the grade total does not include questions set as extra credit. I need to be able to award extra credit points to students who do the extra credit questions/essay without that being included in the necessary grade. If I want the grade to be out of 150 points, and I include 162 points possible by including extra credit essays, I need the listing in the gradebook and the number used for computing the grade percentages, to be out of 150, not 162 points, for example. I will review the exams after the computer has graded the "objective" portions and add points for the essay answers. But the system listing the whole exam out of 162 points means that the essay ISN'T extra credit al all.
In addition, how do I set weighting of scores? If I want this 150 point exam to be worth say 20% of the course grade, where do I set that up?