ACT Science calculating questions use basic arithmetic, proportions, averages, and simple unit conversions from the passage—set up the ratio the experiment implies, then compute carefully. They are usually easier than they look if you write one line of setup.
What math you need
- Ratios and proportions from table values
- Percent change and averages
- Reading scales off graphs
- Simple conversions when units are given
Not calculus—Science math is lighter than Math section. Overview in best ACT Science strategy.
Process
- Find the exact rows/columns the question names.
- Write the relationship in words, then as a fraction.
- Calculate; match units to answer choices.
- Estimate to eliminate absurd options.
Calculator use
You may use an permitted calculator on Science (same test session as Math). For quick arithmetic, mental math is often faster—see ACT calculator policy.
When calculations go wrong
Wrong column, inverted ratio, or percent change divided by the new value instead of the original. Same percent trap as ACT percent problems.
Start practicing
Start with a free diagnostic, then drill your weak spots with 15-question quizzes and track how you're doing across Reading, English, and Math. Compare plans whenever you're ready to go further.
This article offers general ACT prep guidance. The ACT can change from year to year, including its format, scoring, policies, test dates, and fees, so always confirm the latest details on the official ACT website at act.org before you make decisions. ACT® is a registered trademark of ACT, Inc. thirty-six is not affiliated with, endorsed by, or sponsored by ACT.