Kilash how lovely! Tell him his MN aunties are proud. On second thoughts, maybe not! 
Well done on the Olympiad, abitofastate. I’ve just realised when typing your name, I’ve been misreading it ‘as a bit of a taste,’ oops. On taking notes, tell him there are quite possibly no text books at university. If he doesn’t start learning to take notes he might find it a bit of a leap. 
With maths and science a levels, they don’t really get a lot better along the way in the same way as in arts and essay writing subjects. The marks they are getting on end of topic tests in science are likely close to what they’re heading for. Any major improvement will be down to their attitude and how much revision they put in, or so say the science teachers at my school. Maths is all about practice, too.