Not terribly new: 50 years ago (and a few months) a friend of mine rearranged his 11th grade schedule to switch chemistry sections. The wrestling coach teaching

Not terribly new: 50 years ago (and a few months) a friend of mine rearranged his 11th grade schedule to switch chemistry sections. The wrestling coach teaching the one he left, in reviewing the metric system with the students, had defined "milligram" as "one million grams." I trust it was a mere slip of the tongue, but it did not build confidence. On the other hand, my recollection is that coaches taught Algebra I, Plane Geometry, and Trig without causing any scandals. [Edit: corrected the spelling of "wrestling".]