Teaching Them The Whole Nine Yards
(I teach physics to students in a university aviation course in New Zealand. It is like flight school, but with more depth of background knowledge, and you get a degree at the end of it. There are about 20 students, and about half of them are from Asian nations: Malaysia, Korea, Indonesia, etc. The first lesson is unit conversion. I give them some unit conversion factors, like miles to feet and feet to meters, and give some examples, one of which is something like, “Convert 340 yards and 2 feet into miles.” An Asian student raises their hand.)
Student: “What is a yard?”
Me: “I am so happy to find out there are people in the world who don’t know what a yard is. Alas, I am about to destroy your innocent ignorance.”
(I explain inches, feet, yards, chains, furlongs, and miles, to the astonishment of half the class.)