AFQT common mistakes
AFQT · Understand the traps and how to avoid them.
Starts computing as soon as the first two numbers appear in an arithmetic word problem, before identifying the quantity the question asks for.
Word problems feel time-consuming, so candidates latch onto numbers and familiar operations; the final sentence is often read last or skimmed.
What to do instead
Read the entire item once, then write a one-line 'find' statement with units (for example, 'find total cost in dollars') and a rough estimate before choosing an operation.
Uses the wrong base in percent problems-for example, calculating a 20% discount and then a 10% tax on the original price instead of the discounted price.
Percent language such as 'of', 'more than', and 'after' is compressed, and candidates map each percentage to the first number they see.
What to do instead
Label the base after each step and write a chained equation: new price = original × (1 − discount), then taxed price = new price × (1 + tax). Check that the base changes.
Mixes units within a rate or measurement problem, such as dividing minutes by hours or adding feet to inches without converting.
Numbers are presented in compatible-looking forms, and unit labels are treated as decoration rather than as part of the quantity.
What to do instead
Carry units through every operation and convert to a single unit before dividing or adding; reject any answer whose units do not match the requested unit.
Applies the distributive shortcut to squares and roots, writing (x + y)^2 = x^2 + y^2 or √(a + b) = √a + √b.
The distributive property works for multiplication over addition, and candidates overgeneralize it to exponents and radicals.
What to do instead
Test with numbers such as x = 3 and y = 4 to see the equality fail; write (x + y)^2 as (x + y)(x + y) and FOIL; for radicals, simplify by factoring perfect squares inside the radicand.
Solves a linear equation by moving terms across the equals sign without changing signs consistently, producing a sign error in the solution.
Mental arithmetic and shortcut notation hide the inverse operation, especially when negative coefficients are involved.
What to do instead
Show each inverse operation on both sides on a separate line, and substitute the candidate solution back into the original equation before selecting an answer.
Confuses perimeter with area or circumference with area because the formulas share numbers, then selects an answer in the wrong unit.
Formulas are memorized as strings rather than as quantities with units; answer choices often include both values.
What to do instead
Write the formula with a unit cue: perimeter is a length in units, area is in square units, volume is in cubic units; sketch the figure and label what is being measured.
Chooses a synonym by overall sound or topic association rather than by precise meaning, picking a word that is merely related to the stem word.
Vocabulary items use plausible distractors that share a context or connotation; candidates recognize the topic but not the definition.
What to do instead
Before reading options, write a short definition or sentence using the stem word; then test each option by substituting it into that sentence and eliminate any option that shifts meaning.
Misses the direction of the question-treating an antonym item as a synonym item or ignoring whether the stem says 'most nearly means' versus 'opposite'.
The question stem is skimmed under time pressure, and the first option that feels related to the word is selected.
What to do instead
Underline the task word in the stem and circle the stem word; after choosing, re-read the stem to confirm the relationship matches.
Selects an answer based on personal knowledge or opinion about the passage topic rather than on information stated or implied in the passage.
Familiar topics trigger prior beliefs, and answer choices often sound true in the real world.
What to do instead
For every option, locate the supporting sentence in the passage or mark it unsupported; eliminate any choice that cannot be tied to specific text.
Picks a true detail from the passage when the question asks for the main idea, author's purpose, or an inference.
Detail options are concrete and easy to verify, while main-idea options are broader and require synthesis.
What to do instead
Classify the question first as main idea, detail, inference, or tone; then apply the matching test: the main idea must cover the whole passage, a detail must answer the specific stem, and an inference must follow necessarily from the text.