Doesn't university math have tutorials and colloquiums? If you go to MIT opencourseware and look at the math and applied math courses tutorials are a big part. They're done in class to guarantee some minimal understanding. I think its the case with most math departments (not just elite ones like MIT). Not sure if something like that is possible. If you scale out of tutors with maybe a 1:3 or a 1:4 tutor to student ratio it might raise the bar for everyone. It might require a whole bunch of money though.