Understand the format of the math section. It consists of 60 questions in 60 minutes and each question has five choices; the other sections only have four choices. A graphing calculator is permitted. Unlike the SAT, there is no "guessing penalty," that is, if you get a question wrong, there are no points subtracted from your score, so always guess even if you have no idea what the answer is.
Exactly 40% of the ACT math questions (that is, 24) will cover pre-algebra and basic algebra. Make sure that you can solve systems of linear equations, factor quadratics, and understand functions. Brush up on exponents and radicals as well. Practice doing these questions quickly since they are the easiest.
Exactly 30% of the questions (18) will cover intermediate algebra and coordinate geometry. Study the equations of conic sections, quadratic formula, inequalities, and intersections of the graphs of functions. Ask for help from a friend, teacher, or tutor if you haven't done these problems in a while.
The remaining 30% of the ACT math is geometry and a small number of trigonometry questions. Review formulas for finding area, circumference, and perimeter. Also know how to set up equations involving trig functions and the sides of a right triangle. Getting a good score requires knowing how to do questions that combine all these concepts above.
Graphing calculators are programmable, so before test day, write a program for math notes. If you don't know how to program your calculator, consult the instruction book or ask a friend or teacher. Always do ACT practice tests with a calculator to get an accurate score.
If you don't know how to solve a problem, use your calculator to guess and check the answer choices. If the choices are numbers, plug them back into the problem to see which one works. If the choices are equations, plug numbers into the equations to see which one gives you an answer that makes sense according to the problem.
If you get stuck on a question, circle it in the ACT test book and put a light check mark on the answer grid so that you know to come back to it later. Spend your time wisely on the problems that are easiest for you to do. All the problems are counted equally, so don't waste valuable time on ones you can't solve. When time is almost up, go back and fill in any bubbles you missed, even if you have to guess.
When you take practice tests at home, always set the timer. Good ACT preparation includes mastering the math content and building up speed.