ACT Math covers a broad range of topics. Some questions test concepts you may have learned in elementary school, such as simple percent questions and adding or subtracting fractions. Other ACT questions test concepts you may not learn in high school at all, such as matrices and vectors.
There is no overall formula sheet provided for the ACT. Some individual questions may provide a formula, but the majority won’t.
The good news is that if you’re thinking about taking the ACT, you probably already have many of these formulas memorized, or can recall them with a quick refresher or two. With the right prep, you might also have other tools and strategies (such as breaking shapes into smaller shapes) that allow you to solve the problem without using a formula. You’ll still need to memorize some formulas, but not as many as you might fear.
Prioritize your studies by memorizing formulas in this order:
As you go through the Must Know formulas below, mark each one as something you:
For the “Definitely Understand” formulas, you’re done-there’s no need to spend any time memorizing formulas you already know. Instead, focus your efforts where you’ll gain the most.
For the “Sort of Understand” and “Don’t Understand” categories, use your favorite memorization strategy: flashcards, apps, writing in a notebook, etc. If you have more than 10 or so formulas to memorize, focus on about 10 at a time.
After mastering the “Must Know” formulas, repeat the same approach with the “Nice to Know” and “Could Know” formulas.
Try to solve some ACT practice questions (or even better, ACT practice tests ) and review your results. This can make it clearer which formula-based questions you’d be able to solve if only you remembered the formula.
Regardless of your approach, spend some time each day studying your ACT formulas. You’ll see more improvement spending 5-10 minutes a day rather than spending 2 hours once a week cramming.
Most of the formulas you need to memorize for ACT Math are geometry formulas. If you find that you’re missing numerous geometry questions on your homework and practice tests, consider whether your lack of knowledge of the formulas is affecting your score.
Right Angle: 90°
Straight Line: 180°
Triangle: 180°
Circle: 180°
Two kinds of angles are formed: big angles and small angles.
Each big angle is equal to the other big angles.
Each small angle is equal to the other small angles.
Any big angle plus any small angle is 180°.
(use the Pythagorean theorem)
Some ACT Coordinate Geometry questions are really just geometry questions in disguise, but other questions will require formulas specific to this area of study.
Slope:
y -intercept:
(sometimes given in a question)
There are a couple of formulas that are useful when specifically working with quadratics in the form ax ^{ 2 } + bx + c = 0:
Quadratic formula:
Discriminant: D = b ^{ 2 } – 4 ac (the expression under the radical in the quadratic formula)
The sum of the roots:
The product of the roots:
The midpoint of the roots/the
x -coordinate of the vertex:
Most questions testing the following formulas can be solved with careful reading and strategy. However, if you’re the sort that prefers to memorize, these can be helpful to know.
Most ACT Math statistics questions will test basic formulas that you learned in middle school. However, there may be a few questions testing some more advanced statistics concepts.
Knowing the ACT math formulas can be very helpful when taking your exam. However, the bigger challenge is learning effective strategies to answer questions correctly and quickly. The Princeton Review offers books, courses, and tutoring to help you learn the approaches needed to beat ACT Math and earn the score of your dreams.
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