I've been substitute teaching part-time since the start of the year, and I think the district likes me because I tend to want to do science and math classes (which scares off some subs). I've found that I still retain enough basic math, algebra, geometry, and even calculus to be able to help the kids out if they get stuck. But the trig classes I'm out to sea with, especially after the first couple of weeks. I just tell the kids "my trig is rusty, sorry." I think 'corroded' is more accurate, actually; it was never very good to begin with. 8)

And I have to say, the calculators they have these days are an improvement from when I was taking math. I wish they'd had graphing calculators available, for example.