Do you have a textbook? I was one of the weird students (and the only one) in the Honors Algebra II classes that actually read the textbook from cover to cover.
I created a running joke that goes something like this: "Calculus easy, Algebra II hard!" And it applies to any math class. "Algebra II easy, arithmetic hard!"
In all seriousness though (read your textbook), do as many practice problems as you can. I'm sure your math teacher will say, "tonight's homework is 1-30, odds only." Do all of the 30 questions, then finish the rest of the problem set in the section.
I recently read the MCAT FAQ, and it said to do as many practice problems as you can. The more practice problems you do, the better you will be to identify potential shortcuts to solve problems. Even if you have never seen a type of question before, you'll be able to call upon your basic skills to tackle the problem step by step.
Best of luck to you.