SAT or SAT Subject Tests?

Test Preparation
1

I am applying for Waseda University, Faculty of Science and Engineering, in Japan. But there is absolutely no information about what is important to apply for this university. So my question is: Is it better to improve on the SAT or SAT Subject Tests?
The university require the SAT, Chemistry, Physics and Mathematics. I can supply the question with my current scores and an SAT estimate if it is necessary.

2

Im a little confused…have you not done neither the SAT or the subject tests? If you have done the sat, but no the subject tests, i would say take the subject tests cuz the school requires it.

3

Sorry for being unclear, I said: Is it better to improve on the SAT or SAT Subject Tests?
Trying to infer that I have taken both already, but have the opportunity to improve one of them before I try to apply for a university.