Gradebook

I have the same issue. Our metacourse is a program that contains 30 child courses, and each child course has lots of different activities. I am wanting to have the students have a running grade point average as they progress over three years through those 30 courses and I thought that making the 30 courses "child" courses of a metacourse would do the trick - that the grades from the child courses would somehow be transferred into the grade book for the metacourse, but, it did not "just happen" that way and I don't know how to get it to do that. Any ideas? Or is the structure I have chosen not the right way to achieve the result I desire?

Thanks

Amy