A page full of free econ courses:
https://ocw.mit.edu/courses/economics/including this OCW Scholar first-year college complete self-paced online course, with video lectures, online text, problem sets, solutions, video recitations, exams, etc.:
https://ocw.mit.edu/courses/economics/14-01sc-principles-of-microeconomics-fall-2011/It does require some calculus to actually do the problems, but I don't see why he couldn't watch the videos and do some of the readings, if he isn't there with the math yet. Or you could just teach him the calculus. There's an OCW Scholar class for that, too...
