ACT® · Math: Pacing, Four Choices, and Question Strategy
The Calculator Policy and How to Use It
Calculators are allowed on the math section except models with a computer algebra system that manipulates symbols directly, and having one in hand doesn't make you faster if you reach for it on arithmetic you could do in your head.
The rule is simple once you see what it's protecting against. The section wants to measure whether you understand the math, not whether your calculator can solve equations for you. So the one banned class is computer algebra system calculators: machines that manipulate symbols, solve for x, or factor expressions on their own. Everything else, including most graphing and scientific calculators, is fine to carry in. The rule targets a capability, not a brand or a price tag.
That capability-based rule doesn't change when the format does. Testing on a screen instead of on paper, you get a built-in calculator inside the platform rather than one in your hand. Same forty-five items, same rules underneath: no symbol-solving tool, no exceptions for going digital. The on-screen version is a convenience, not a loosened policy.
Here's the part that trips people up: owning a calculator and using it well are different skills. On a two-step arithmetic problem, like finding 15 percent of 240 and then subtracting it from 300, picking up the calculator means finding it, turning it on, and keying in each step. That costs real seconds. Doing the two steps in your head, or on scratch paper, often beats the keystrokes. With sixty-seven seconds per item on average, those seconds matter. The calculator is a tool for the moments that need it, like messy decimals or square roots, not a reflex for every arithmetic line.
Key terms
- Computer algebra system (CAS)
- Software that manipulates symbols and solves equations algebraically, the one calculator class banned from the math section.
- Built-in calculator
- The on-screen calculator provided inside the testing platform when taking the exam online instead of on paper.
- Capability-based rule
- A policy that bans calculators by what they can do, like solving symbolically, rather than by brand or model name.
- Two-step arithmetic
- A calculation requiring two sequential operations, like multiplying then subtracting, often faster done mentally than keyed in.
Watch it explained
- How it worksHow does the ban on computer algebra system calculators decide which models you may carry in?
- Going furtherWhat changes about calculator use when you test online and use the platform's built-in one?
- Common mistakeWhy isn't grabbing the calculator the fastest move on a two step arithmetic item?
Check yourself
End of topic.