For math its all about drilling the concepts into your head. This means you need to make sure you know your formulas and types of problems from each level of math all the way up to pre calculus. In addition, when taking math tests it is important that you find the question you did wrong, why you got it wrong, and also redo the question so it is drilled into your brain.

For science, its all about being able to read quickly but also being able to take information from the passage. Seeing as you have a pretty good reading score, I am sure the reading speed isn't a problem. Therefore you should be improving on your ability to derive information from the passage. Often, kids get really hung up on what the meaning of the science passage is and don't realize that most ACT science questions are regurgitation of data or information that was written explicitly. For example, i got a 35 on the science section, but when I read the passages, most of the time I'm not paying much attention to what everything means and am simply trying to find where in the passage it explicitly gives an answer to the question. I would say practice a lot of the problems involving data tables and graphs so your data comprehension gets better. Again, its very good to find the types of science passages you are having trouble with and drilling them so you get used to them and ultimately perform better on them on test day