Hello Ellen. I am moving your post to the dedicated quiz forum (you don't need to do anything - you should still receive any replies as normal) One thing to look at is (and I know because I have done this myself) - did you set a grade for the quiz?
- Go to your course and click on the quiz
- There should be a block on either the left or right side that says Quiz administration
- Click the link Edit quiz
- Look and see if the box over on the right 'Maximum grade' has a grade in it.