The two biggest challenges of ACT Math are the time crunch—the math test has 60 questions in 60 minutes!—and the fact that the test doesn’t provide you with any formulas. All the formulas and math knowledge for the ACT comes from what you’ve learned and memorized.
In this complete list of critical formulas you'll need on the ACT, I'll lay out every formula you must have memorized before test day, as well as explanations for how to use them and what they mean. I'll also show you which formulas you should prioritize memorizing (the ones that are needed for multiple questions) and which ones you should memorize only when you've got everything else nailed down tight.