From an interview with John Gatto (NY City, teacher of the year):

"It's funny, you can take five-year-olds off the street, and teach them in about two weeks to do all the arithmetic operations mentally ? really, up to multiplying four or five figures! That's all it would take, two weeks. Even accomplished mathematicians say that the entire mathematics curriculum through calculus and trig takes about 50 contact hours to deliver.

The consensus is that it takes 30 contact hours to bring someone to the point where they can be a self-teacher in reading for the rest of their lives."