Maybe college-level math is different from math taught in a maths depart? Either way, the common errors mentioned in the article appear to be, well, elementary.

Maybe college-level math is different from math taught in a maths depart? Either way, the common errors mentioned in the article appear to be, well, elementary. I'd imagine 6 or 7 graders make those mistakes, but college students? Shouldn't they make mistakes like "there is no function that is everywhere continuous but nowhere differentiable", or "isomorphism of factors implies isomorphism of quotient groups"? The webpage says a lot about the quality of the K12 education in the US.