I would like to have the feature to limit the number of attempts the student can have on an assignment.

Hi Mkarns,

Thanks for writing in with your idea! We are always working to add features that improve our site, and we love getting input from our community.

I've passed your feedback along to the team and it will be part of our conversation as we plan the future of Khan Academy.

Thanks again for your interest in improving Khan Academy :)

All the best,