According to BLS, the median pay is $53,230 per year, which would be closer to $26.50 an hour, assuming a 40-hour work week.
http://www.bls.gov/ooh/education-training-and-library/high-s...
Maybe the Forbes article you're referring to about is only counting classroom hours, which is a pretty absurd notion. Teaching is a full-time job, and any figure based on an assumption to the contrary is going to be flawed. Not meaning to straw-man you, it's just that without a link to the article in question, I can only speculate where your figures come from.