All schools make time for non-classroom activities and/or non-academic classes. Chapel, art classes, sports teams, club, advisories, volunteer work.
They have a schedule that makes it particularly easy to create time for that.
I am sure that they have worked it out so that it is math AND social justice activity, no math OR social justice activity. Personally, I really like CSW. It’s a great school for a lot of different kinds of kids.