ACT Science Practice: How to Train for the Optional Section

By James L., Test Prep Specialist

The direct answer: ACT® Science is an optional 40 minute section with 40 questions that tests your ability to read graphs, tables, and study designs, not your memorized science facts. On the redesigned ACT, science is no longer part of the Composite. If you take it, you also receive a STEM score, which some engineering and science programs consider (ACT's official test information). A good practice routine trains data interpretation a little every day, not biology recall.

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ACT Science at a Glance

What the Section Actually Tests

The redesigned ACT science section keeps three reporting categories: Interpretation of Data (38 to 50 percent), Scientific Investigation (18 to 32 percent), and Evaluating Scientific Arguments and Models with Evidence (24 to 38 percent) (ACT's official test information). Notice what is missing: no question asks you to recite the Krebs cycle. The skill is reading.

This is good news if your science coursework is light. The passage gives you the facts. Your job is to pull the right ones out fast.

Interpretation of data

These give a graph or table and ask you to read a value, spot a trend, or compare sets. The trap is rushing the axes. Name the units in your head before you answer, because a question about "rate per minute" is easy to misread if the axis says "per hour."

Scientific investigation

These ask about experiment design: variables, controls, what a changed setup would show. You need no outside knowledge, only the ability to read the method described. If the passage says the control group got no fertilizer, the question about the control is answerable from that sentence.

Evaluating arguments

These give two scientists who disagree and ask which evidence supports whom. Match the claim to the data. Do not pick the opinion you personally agree with, because the score depends on what the passage shows, not what is true in the real world.

A Daily Practice Routine

Daily: one passage, ten minutes

Use ACT's free timed practice, which includes science passages in the current structure (ACT sample questions and practice). One passage a day beats a weekly cram, because the skill is pattern recognition. You are teaching your eyes to find the axis, the variable, and the claim quickly.

Weekly: argue the viewpoints

Take one conflicting viewpoints passage and write, in a single sentence, what each scientist claims and which graph backs it. This exposes the weak link between a statement and its evidence, which is exactly what the arguments category measures.

Review: log by category

Tally misses by the three categories. If investigation questions lag, drill experiment design next. A simple spreadsheet with three columns is enough. The point is to see the pattern, not to feel busy.

How to Practice Without a Science Background

Students worry they need heavy science coursework. They do not. The section provides the facts in the passage.

Read the figure first

Spend 30 seconds on the graph or table before the questions. The questions then become lookups. This one habit removes most of the panic, because you already know where the numbers live.

Use a study partner for viewpoints

Conflicting viewpoints are easier with a second reader. Talk the two positions out loud and force yourself to name the evidence for each. Speaking the claim and its support builds the exact skill the arguments category tests, and a partner will catch you when you drift to your own opinion.

Common Misconceptions

• "Science tests my science knowledge." It tests data reading.
• "Always skip it." If your colleges want the STEM score, skipping costs you a useful data point.
• "Memorize formulas." The figures give you what you need.
• "Read the passage slow." Read the figure first, then the text.
• "It is the hardest section." It is among the most learnable with daily drills, because it rewards a repeatable method.

A Worked Example: Reading the Figure First

Concrete practice shows the method. A graph plots enzyme rate against temperature, peaking at 37°C, then falling. A question asks what happens to the rate at 45°C.

The answer is on the graph: the line falls after the peak, so the rate drops. You need no biology fact beyond reading the axis. A student who recalls "enzymes denature" may be right in real life, but the mark comes from the plotted trend. The passage is the authority, not your textbook.

The conflicting viewpoints move

Two scientists disagree on a cause. Before reading their claims, note the data each cites. Then match claim to evidence. This is where a study partner helps, because saying the link aloud exposes a weak connection you might otherwise miss.

Your First Month Checklist

• Days 1 to 4: one data passage daily, figure first.
• Day 5: one research summary, underline the variables.
• Day 6: one conflicting viewpoints passage, write each claim and its evidence.
• Day 7: tally misses by the three categories.
• Weeks 2 to 4: repeat, then add one full science section from official practice (ACT sample questions and practice).
• Every week: resurface the weak category so it does not go cold.

Test Day Routine

If you sit the optional science section, the routine keeps the data reading clean.

• Sleep and eat. The section follows the core test, and focus is the main risk.
• Read the figure before the text on every data passage. The answers are plotted.
• Underline the variables in research summaries. Questions turn on them.
• For viewpoints, match each claim to its evidence. Do not pick the one you like.
• Hold one minute per question. Mark the slow viewpoint passage and return.
• Guess on every blank. There is no penalty, and four choices reward a guess.

Frequently Asked Questions

Is ACT Science optional?

Yes, on the redesigned ACT it is an option and is not part of the Composite (ACT's official test information).

How many questions and how long?

Forty questions in 40 minutes.

What does it test?

Data interpretation, investigation design, and evaluating arguments, not facts.

Does taking it give an extra score?

Yes, a STEM score if you take science with math.

Do I need a science background?

No. The section provides the facts in the passages, so data reading matters more than coursework.

How should I practice?

One passage a day with the figure first, then a full section weekly from official practice.