If you regard the numbers as the gear you take the corner in, you'll have it pretty much cracked. not all cars have 7th gear but take 6&7 flat out, 5 pretty much flat out with a good line, maybe lift slightly then 4 in 4th, 3 in 3rd etc. sometimes he can be a bit late with them but most of the time you'll absolutely nail it if you use this basic formula. when he says something like 1 long, or 2 long it's usually a double apex bend or just simply a long single apex bend. When he says 500, 600, over 1000 etc that means a straight (or maybe slight kink) of roughly that length in metres. In other words if he says over 1000 then get your toe down without fear of a bend! hope this helps