I'm working on setting up a course with 3 required assignments and a suite of optional ones (assignments and discussions) that they can choose from. 

How do I set this up? I thought at first it would be as easy as not having the ungraded items =0, but there are required assignments that should be 0s if not completed. Also, as the course is originally designed, they should be working towards a total percentage of points earned. In other words, the required assignments are 50% of their grade, and they should choose enough optional assignments to equal another 50% of their grade (whether or not they earn a perfect score on those assignments). 

Then I thought I'd set up the optional assignments in an assignment group and drop the lowest grades, but there aren't a certain number of assignments they have to do... There's a grade they can work towards, but each of the optional assignments are worth a different amount of points. So, they could do one 40 point research paper or participate in eight 5-point discussions and get the same grade.

Any ideas? If it helps, we're on the New Gradebook.