ATI TEAS cheat sheet

Main idea is the central point the entire passage supports; it is broader than any single detail and is often stated in the introduction or conclusion.

Supporting details answer who, what, when, where, why, or how, and every one should be traceable back to the text.

An inference is a conclusion that follows logically from stated evidence but is never stated directly by the author.

Author's purpose falls into four common categories: inform, persuade, entertain, and instruct or describe.

Text structures to recognize: compare-contrast, cause-effect, chronological, problem-solution, and description.

A fact is verifiable by evidence; an opinion is a judgment or belief, often signaled by words such as should, best, or seems.

A claim is only as strong as its evidence, which must be relevant to the claim, sufficient in amount, and free of bias.

Context clues come in four main types: definition or restatement, example, contrast, and general sense of surrounding sentences.

The title, first sentence, and final sentence of a passage usually reveal its topic, scope, and the author's attitude.

Order of operations: parentheses, exponents, multiplication and division left to right, then addition and subtraction left to right.

Percent change = (new value − old value) ÷ old value × 100.

Part = percent × whole; whole = part ÷ percent; percent = part ÷ whole × 100.

A proportion a/b = c/d is solved by cross-multiplying: ad = bc.

Slope = (y₂ − y₁) ÷ (x₂ − x₁); slope-intercept form is y = mx + b.

Mean = sum ÷ count; median = middle value of ordered data; mode = most frequent value.

Area: rectangle = lw, triangle = ½bh, circle = πr²; circumference = 2πr; volume of a rectangular prism = lwh.

Multiply fractions straight across; divide fractions by multiplying by the reciprocal of the divisor.

Absolute value is distance from zero, so |−7| = 7 and |x| can never be negative.

Unit conversion is done by multiplying by a conversion factor in which the numerator and denominator are equal quantities.

Cell theory: all living things are made of cells, cells are the basic unit of life, and new cells arise from existing cells.

Organelle functions: mitochondria produce ATP, ribosomes build proteins, chloroplasts carry out photosynthesis, nucleus stores DNA.

Mitosis produces two identical diploid cells; meiosis produces four genetically unique haploid gametes.

Homeostasis is the maintenance of stable internal conditions such as temperature, pH, and blood glucose despite external change.

Newton's laws: objects at rest or in uniform motion stay that way unless a net force acts (F = ma), and forces occur in equal, opposite pairs.

Speed = distance ÷ time; acceleration = change in velocity ÷ time; density = mass ÷ volume.

On the pH scale, below 7 is acidic, 7 is neutral, and above 7 is basic; each whole unit is a tenfold change in hydrogen ion concentration.

Dominant alleles mask recessive alleles in the phenotype; a Punnett square predicts offspring genotype and phenotype ratios.

Atomic structure: protons are positive and neutrons are neutral (both in the nucleus), while electrons are negative and occupy orbitals.

Subject and verb must agree in number; ignore prepositional phrases between them when deciding which form to use.

A pronoun must agree with its antecedent in number and gender.

An independent clause contains a subject and a verb and expresses a complete thought; lacking either produces a fragment.

Join two independent clauses with a semicolon, or with a comma plus a coordinating conjunction (for, and, nor, but, or, yet, so).

An apostrophe marks possession ('s for singular, s' for plural) or a contraction; it never forms a simple plural.

Commas set off items in a series, introductory phrases, nonessential clauses, and clauses joined by a coordinating conjunction.

Active voice: the subject performs the action. Passive voice: the subject receives the action and often hides the actor.

Commonly confused pairs: their/there/they're, its/it's, and affect (usually a verb) versus effect (usually a noun).

Capitalize the first word of a sentence, proper nouns, and a title preceding a person's name.