It's just intuitive coincidence that high-scoring students do a high level of maths. You can loosely define subjects as either artistic, theoretical or logical, and maths is known to be the basis of logic. People who are good at maths thus have a better aptitude for physics and chemistry. 4u maths, 2u physics, 2u chem and the compulsory 2u english is your 10 HSC units already.
Now to my question which I feel selfish creating a new thread for:
4u Maths means that Ext 1. counts for 2 units and Ext 2. counts for 2 units.
What if you do 3u maths? Is it like english where the extension unit only counts for 1 unit?
The reason I ask is because for a student who is not adept enough at maths for 3u maths to be relatively easy, Ext 1. maths then becomes a whole lot of hard work for only 1 unit of credit.