<p>My understanding is that Math 11 is essentially a combination of the second half of math 8 and all of math 13 for those who did Calc BC as opposed to only Calc AB is high school. Which means that if the prof is right and he needs math 11 for that econ class, he will now need to take math 8 and math 13 in addition to the math 3 he is repeating now before he will have the right background for the econ class. If he was self taught this may have been the right decision, but if you go by the profs logic, it will be several semesters, i.e. next winter, before he has the calc background for econ 21.</p>