At our community centers we use Edubuntu. Similarly Edubuntu is currently used in many schools and other educational institutions around the globe. It is sad to know that project is not quite active due to lack of contributors.
http://news.softpedia.com/news/edubuntu-16-04-xenial-xerus-will-not-be-a-long-term-support-lts-release-502003.shtml
I would suggest that you use Debian Edu for your needs. Considering our understanding when it comes to Ubuntu, it would be a good idea to move to a free as in freedom distro