Thanks wolvesaussie and milliem. He can tutor primary, secondary and tertiary level students. As for the teaching of two specialisms, he had to do that in the state system here in the UK, and didn't like it. It's one of the reasons he now teaches in a private school. I've noticed that private schools in Oz, like in the UK, are less likely to require teaching of multiple subjects (which makes sense, he spent 10 years at uni developing expertise in mathematics, not science, so is a great and effective maths teacher, not so keen on the science!) Expert subject knowledge is absolutely critical to effective teaching. I'm sure that one of the reasons the UK has plummeted down the OECD rankings in educational achievement is the fact that in state schools here many teachers are not graduates in their teaching subject. It would be very sad if Oz went the same way, especially in critical subjects like maths and science.