Here’s my question. Quite often I’ll hear an American expert on the news say something like “it’s Economics 101” and from context clues I can tell they’re alluding to a beginner’s class or a bare-bones introduction to the subject, but what are the origins of this number and where does it come from?
I assume it has something to do with the American education system, but at what level are we talking - High School, College, etc.? Why does the numbering start at 101 instead of say 1? What’s the next class after the beginner one, 102? 201? And how far does it end up going or does that depend on the subject?