Written by: Eric Kim, Founder of Matter
Updated:
June 18, 2026
Introduction
Most guides tell you what the ACT contains. This one explains what each part is measuring underneath, because that determines how best to prepare for each section. The ACT has three required sections (English, Math, and Reading) and two optional sections (Science and Writing). Every section is designed by ACT Inc. to reflect skills students develop in school.
This is Matter’s parent guide to the skill behind each section. For the full orientation, start at our ACT Resource Hub.
How the ACT thinks about ability
The ACT is curriculum-aligned, meaning it is designed to reflect what students learn in high school rather than test obscure tricks or last-minute memorization. It is also linear, not adaptive, which means every student at a given administration sees a comparable test, with no mid-test difficulty shifts like the SAT.
This design affects how best to prepare for the exam. Some skills compound slowly over many months, like reading fluency and close reading. Others respond to focused weeks of practice, like a specific algebra procedure or a punctuation rule. Knowing which section a weakness sits in tells you whether the fix is a habit or a drill.
English: editing and rhetoric under time
What ACT says it measures: grammar, usage, and rhetorical skills, applied to revising and editing short texts and essays across genres. ACT groups the questions into three areas: Production of Writing (38–43%: topic development, plus organization, unity, and cohesion), Knowledge of Language (18–23%: precise and concise word choice and consistent style and tone), and Conventions of Standard English (38–43%: grammar, usage, and mechanics, including sentence structure, punctuation, and usage).
What the section is actually testing: control of standard written English and the judgment to make prose clearer and tighter, applied to passages rather than isolated rules. It rewards students who can spot redundancy, fix sentence structure, and pick the most concise option under time pressure.
What this means for your prep: Conventions questions reward a focused review of a finite set of punctuation and sentence-structure rules. Production of Writing rewards reading for a paragraph’s purpose. Both are trainable in a short amount of time, which makes English one of the faster sections to move.
Sample question:
The annual conference, which happens each year, drew a record crowd.
Which choice is most concise and appropriate?
(A) NO CHANGE
(B) which happens annually,
(C) DELETE the underlined portion
(D) that happens each and every year,
Answer: C. “Annual” already means each year, so the clause is redundant. Deleting it is the most concise fix.
Mathematics: reasoning through the start of grade 12
What ACT says it measures: mathematical reasoning from pre-algebra through trigonometry. ACT groups the content into two categories: Preparing for Higher Math (~80%: algebra, functions, geometry, statistics and probability, number and quantity) and Integrating Essential Skills (~20%: rates, proportions, averages, and measurement in real-world contexts).
What the section is actually testing: translating a described situation into an equation, then executing cleanly. A calculator is permitted, so setting the problem up correctly matters more than raw computation speed.
What this means for your prep: Preparing for Higher Math carries most of the weight, so a student short on time gets the best return there. Word-problem set-up is a trainable skill and often the fastest score-mover.
Sample question:
A jacket is marked down 20% from its original price to $52. What was the original price?
(A) $62.40
(B) $64
(C) $65
(D) $72
Answer: C. If 0.80 × p = 52, then p = 65.
Reading: close reading across text types
What ACT says it measures: close reading, logical reasoning, and integrating information across literary and informational texts. ACT groups the skills into three categories: Key Ideas and Details (44–52%: central ideas, summarizing, inferences, and sequential, comparative, and cause-effect relationships), Craft and Structure (26–33%: text structure, word and phrase meaning, and an author’s choices), and Integration of Knowledge and Ideas (19–26%: understanding claims, distinguishing fact from opinion, and connecting evidence across texts).
What the section is actually testing: reading accurately and quickly enough to locate evidence and draw an inference under time pressure. It is less about outside knowledge and more about tracking what a passage actually says.
What this means for your prep: this is the section that rewards long-horizon reading habits most, so it responds slowly to drilling. In the last few weeks before test day, timed passages with active reading is the best use of your time.
Sample question:
A passage describes a marine biologist who resisted using drones for whale surveys, then adopted them after the footage revealed feeding behavior her boat-based team had missed.
The passage most strongly suggests her change of view was driven by:
(A) pressure from her funders
(B) the evidence the new method produced
(C) a shortage of research boats
(D) a colleague’s insistence
Answer: B. The passage ties her shift to the evidence the drones revealed, not to outside pressure.
Science (optional): reasoning from data
What ACT says it measures: data interpretation, analysis, reasoning, and problem-solving across biology, chemistry, Earth and space sciences, and physics. ACT groups this into three categories: Interpretation of Data (38–50%: reading data in tables, graphs, and diagrams, spotting trends, and applying basic math reasoning), Scientific Investigation (18–32%: experimental design, variables and controls, and predicting or extending results), and Evaluating Scientific Arguments and Models with Evidence (25–35%: judging the validity of scientific claims from evidence and drawing conclusions and predictions).
What the section is actually testing: interpreting and understanding graphs, tables, and experiments quickly, not recalling science facts. Most questions are answerable from the figures on the page.
What this means for your prep: Drill full science sections under time, pulling each answer straight from the graphs, tables, and experiments on the page. What improves is your speed at reading figures, not your science knowledge, so get comfortable trusting the data in front of you and knowing which types of questions require you to actually read the passage.
Sample question:
A table shows a solution’s boiling point rising with added salt: 0 g → 100.0°C, 10 g → 100.3°C, 20 g → 100.6°C, 30 g → 100.9°C. Based on the trend, the boiling point at 40 g would most likely be:
(A) 99.6°C
(B) 100.0°C
(C) 101.2°C
(D) 102.0°C
Answer: C. Each added 10 g raises the boiling point about 0.3°C. Extending that trend gives roughly 101.2°C.
Writing (optional): building an argument
What ACT says it measures: the optional Writing test gives a prompt describing a complex issue and three perspectives. The student develops their own position and analyzes its relationship to one or more of the given perspectives.
What the section is actually testing: staking out a clear thesis and supporting it under time, while engaging the perspectives you are given. There is no single correct position. The score rewards a focused, well-developed argument. For a breakdown of how exactly your essay is scored, see our ACT score report guide.
What this means for your prep: Write a few timed essays to a structure you can repeat: take a clear side in your opening, engage at least one of the given perspectives, and back your position with specific reasons while writing an essay that is structured and transitions logically. Doing this under strict time constraints tends to be the biggest obstacle.
Sample prompt:
The Gig Economy
Over the past decade, app-based platforms have made it possible for millions of people to earn money as independent contractors, setting their own hours to drive, deliver, or freelance online. Supporters say this flexibility gives workers a freedom that traditional jobs never offered. Critics answer that gig work strips away the stability, benefits, and protections that come with steady employment. As more of the economy shifts toward short-term, on-demand work, it is worth asking what we gain and what we lose when the reliable job gives way to the flexible gig.
Perspective One: The gig economy is a win for workers. Choosing when and how much to work is a kind of freedom most traditional jobs cannot match.
Perspective Two: Flexibility means little without a safety net. With no health insurance, paid leave, or job security, gig workers carry all of the risk themselves.
Perspective Three: The gig economy is neither savior nor villain. It is a tool, and whether it helps or harms workers depends on the rules we build around it.
Essay task: State your own perspective on the issue and analyze the relationship between your perspective and at least one other perspective. Support your position with reasoning and specific examples. Your position may agree fully with any of the perspectives given, partially agree, or differ entirely.
What’s common and what’s distinctive
All four multiple-choice sections work the same way: questions are grouped into ACT’s published skill categories, there is no penalty for guessing, and each one is scored from 1 to 36. Where they differ is how far ahead you need to prep. English and Math reward focused practice in the final weeks. Reading leans on reading habits built up over months/years. Science comes down to practicing under time so you can read data quickly.
The bigger question is often which sections to take in the first place. English, Math, and Reading are required, and together they make up the Composite score. Science and Writing are optional, and your child chooses them at registration. We walk through that decision in the enhanced ACT guide. For the full set of guides, return to the ACT Resource Hub.