I would use flashcards for math terms and formulas, and practice extra problems for math skills. Just remember, don't study for more than an hour without breaks. Take plenty of 5-10 minute breaks in between. It also helps if you eat mints/minty gum as this is proven to keep you focused. Turn of ALL electronics, unless you play music, which you should not unless it is classical music, as this is also proven to improve focus.