Teaching has rare days where the mistakes, the "not yet learned" of young people cause the corners of ones mouth to smile, before rolling one's eyes at how little we have managed to communicate.
Today was one of the those days. Year seven baseline assessment (part of which just checks what it is that our students have learned in their previous schools). They were asked to define some historical terms- including CE and BCE (the trendy new forms of AD and BC.. they mean Common Era, and before the Common Era). You can imagine my smile then, as I read that actually CE is Christ's erection, with BCE meaning Before Christ's erection!