Free TEAS 7
study guide & practice.

Find the main idea and the supporting evidence

Main idea = the point the whole passage develops. A detail may be true without being broad enough to summarize the passage. After reading, finish this sentence: “The author mainly explains/argues that…”

Look for repeated concepts, the relationship between the opening and closing, and the reason the details were included. A good summary keeps the central idea and essential support; it excludes your opinion and minor examples.

Worked example: A passage describes a library extending hours, reports who used them, and weighs staffing costs. Its main idea concerns evaluating extended hours, not simply that the library has a director.

Trap: an answer that says “all,” “always,” or “proves” when the passage only describes some people or a possible effect. Match the scope of the evidence.

Inference, conclusions, and text evidence

An inference combines a stated detail with a reasonable implication. It should require the fewest unsupported assumptions. A conclusion can be plausible in real life and still be unsupported by the passage.

1. Identify exactly what the question asks.
2. Locate the relevant sentence, table entry, or pair of statements.
3. Eliminate answers that contradict it or introduce a new fact.
4. Choose the answer supported by the passage, even if another answer fits your personal experience.

Example: A traveler checks the tickets repeatedly. Anxiety is a supported inference. “The tickets were lost” is an invented event.

When comparing two writers, find their actual overlap and disagreement. One writer may support a goal while disagreeing about timing or method.

Purpose, tone, structure, and vocabulary in context

Purpose: inform explains; persuade argues for a position; entertain develops an experience or story; instruct tells the reader how to act. A passage may do several things, but the question usually asks for its primary purpose.

Tone is the writer’s attitude, such as cautious, skeptical, supportive, or neutral. Mood is the feeling created for the reader. First person uses “I/we”; second person addresses “you”; third person describes people as “he/she/they.”

Common structures are sequence, comparison, cause/effect, problem/solution, and description. A transition such as “however” signals contrast; “therefore” signals a consequence.

For an unfamiliar word, substitute each proposed meaning into the sentence. Use surrounding clues, not just a memorized definition. “A modest first phase” usually means a limited initial step, not a shy personality.

Claims, sources, bias, and numerical evidence

A factual claim can be checked; an opinion expresses a judgment or preference. A checkable claim may still be false. A source’s confidence does not prove accuracy.

An authentic firsthand record is a primary source. A later analysis of that record is a secondary source. Evaluate who produced the material, its purpose, supporting evidence, relevant date, and possible conflicts.

Counts versus people: 420 visits may include repeat visitors. Samples versus populations: 72% of survey respondents is not automatically 72% of all residents. Association versus causation: two variables moving together does not show that one caused the other.

Ask what would weaken an argument: a better explanation, missing comparison, unrepresentative sample, or data that contradict the claim. Favor relevant evidence over impressive but unrelated statistics.

Read tables, instructions, schedules, and paired texts

Before using a table or graph, check the title, labels, units, time period, scale, and denominator. Compare like units. A graph with a truncated vertical axis can make a small change look dramatic.

For instructions, distinguish prerequisites, deadlines, exceptions, and conditional permissions. “Request before noon” and “return by 4 p.m.” are different deadlines. A timely request may still fail another condition.

For schedules, compare entire intervals rather than start times. For paired passages, make a two-column note: each author’s claim, evidence, and qualification.

Pacing: 45 reading questions in 55 minutes is about 73 seconds per question on average, including passage reading. Some questions should take less. Flag a difficult item and return within the section rather than losing several minutes on it.

Fractions, decimals, exponents, and order of operations

Add/subtract fractions: use a common denominator. 1/2 + 1/3 = 3/6 + 2/6 = 5/6. Multiply: multiply numerators and denominators. Divide: multiply by the reciprocal: (3/4) ÷ (1/8) = 6.

Terminating and repeating decimals are rational numbers. Integers are rational because n = n/1. Numbers such as √2 and π are irrational.

Order of operations: parentheses; exponents; multiplication/division left to right; addition/subtraction left to right. 6 + 3 × 4 − 8 ÷ 2 = 14. A square root asks which nonnegative number squared gives the value: √49 = 7.

For negative numbers, draw a number line mentally. −0.6 is less than −0.25. Estimate first: multiplying a positive number by 0.5 should halve it, not increase it.

Percentages, ratios, rates, and proportions

Percent means per hundred: 18% = 0.18. Part = decimal rate × whole. If 64 is 80% of a number, solve 64 = 0.80n, so n = 80.

Percent change = (new − original) ÷ original × 100%. From $80 to $100: 20/80 = 25% increase. Use the original amount as the denominator.

A 15% discount on $60 gives 60 × 0.85 = $51. Sales tax of 7.5% on $40 gives 40 × 1.075 = $43. Apply changes in the stated order; successive percent changes generally do not cancel.

For a 3:5 ratio with 40 total items, there are 8 parts: 40/8 = 5 per part; the first group has 15. A unit rate has a denominator of one: 120 miles/2.5 hours = 48 miles/hour. Set up proportions only when the quantities are proportional.

Equations, inequalities, and word problems

Keep equations balanced by performing the same operation on both sides. For 3x − 7 = 20: add 7, then divide by 3; x = 9. Check by substitution.

Distribute across every term: 3(2x − 4) = 6x − 12. Combine like terms, not unrelated terms such as x and x².

Reverse an inequality sign when multiplying or dividing both sides by a negative number. −2x < 8 becomes x > −4. Dividing by a positive number does not reverse it.

Translate a word problem before calculating: define the variable, identify the fixed amount and rate, write the relationship, solve, and check units. A $12 fee plus $4 per session is C = 12 + 4x, not 16x.

For a line, slope = (y₂ − y₁)/(x₂ − x₁). In y = mx + b, m is slope and b is the y-intercept. A steep-looking graph is not enough; use the axis scales.

Measurement and conversion toolkit

Dimensional analysis: write conversion factors so unwanted units cancel. Convert to the same unit before adding or subtracting. Milligrams are much smaller than grams, so the same mass has a larger number of milligrams.

Learn the formulas and check what the real testing interface supplies. Do not assume every practice problem’s reference information will be supplied on test day.

Geometry: recognize the requested quantity

Perimeter uses linear units, area uses square units, and volume uses cubic units. Radius is half the diameter. For a right triangle with legs 6 and 8, c = √(36 + 64) = 10.

Use the value of π and rounding rule requested in the item. Keep intermediate precision and round at the end.

Data, probability, and reasonableness checks

Mean: sum/count. Median: middle ordered value, or mean of the two middle values. Mode: most frequent value. Range: maximum − minimum.

For 2, 3, 3, 4, 8: mean = 4; median = 3; mode = 3; range = 6. One extreme observation can pull the mean much more than the median.

With equally likely outcomes, probability = favorable/total. Three red balls among eight gives 3/8. If draws occur without replacement, update both the numerator and denominator for the second draw.

Before accepting an answer, check magnitude, sign, unit, and whether the question asked for a part or the whole. A $60 item after a 15% discount cannot cost $9; that is the discount amount.

The calculator helps with arithmetic but cannot decide the setup. Use scratch work to write the equation first.

Heart, circulation, respiration, and blood

Blood pathway: body → venae cavae → right atrium → right ventricle → pulmonary arteries → lung capillaries → pulmonary veins → left atrium → left ventricle → aorta → body. Valves promote one-way flow.

Arteries carry blood away from the heart; veins return it. These names describe direction, not oxygen content. The left ventricle has the demanding job of pumping into systemic circulation.

Red blood cells carry oxygen using hemoglobin; white blood cells support defense; platelets participate in clotting; plasma is the liquid component.

Inhalation: diaphragm contracts and descends → thoracic volume rises → lung pressure falls → air enters. Alveoli provide a thin, large surface for diffusion. Oxygen moves into pulmonary blood and carbon dioxide moves toward the alveoli according to partial-pressure gradients. Ventilation is air movement; gas exchange is diffusion.

Digestion, nutrition, kidney function, and fluid balance

Food moves mouth → pharynx → esophagus → stomach → small intestine → large intestine → rectum/anus. Peristalsis propels material. The small intestine is the main site of nutrient absorption; villi and microvilli increase its surface area.

The liver makes bile; the gallbladder stores and concentrates it. Bile emulsifies fat rather than acting as a digestive enzyme. The pancreas releases digestive enzymes and bicarbonate into the small intestine. Its endocrine cells also secrete hormones such as insulin and glucagon.

Kidneys regulate fluid, electrolytes, acid–base balance, and waste excretion. The nephron filters at the glomerulus, reabsorbs needed substances, and secretes others into tubular fluid. Filtration is not the same as final excretion.

ADH promotes water reabsorption; aldosterone promotes sodium reabsorption and potassium secretion. Insulin generally helps lower blood glucose; glucagon helps raise it. Distinguish a hormone’s source, target, and effect.

Nervous and endocrine coordination

The central nervous system includes brain and spinal cord; the peripheral system connects them with the body. Sensory input travels toward the CNS; motor output travels toward effectors. Somatic pathways control skeletal muscle; autonomic pathways regulate many involuntary functions.

A neuron’s dendrites generally receive information; its axon carries action potentials away from the cell body. Myelin speeds conduction along many axons. At many synapses, neurotransmitters transmit a signal across a gap.

A spinal reflex can start a withdrawal movement before conscious pain recognition. Signals can still reach the brain; a reflex does not mean the brain receives nothing.

Hormones travel in blood and act on cells with suitable receptors. Thyroid hormones influence metabolism, parathyroid hormone helps regulate calcium, and adrenal hormones contribute to stress responses. Negative feedback counteracts a deviation; positive feedback amplifies a process, as in the oxytocin-driven childbirth loop.

Muscle, skeleton, skin, immunity, and reproduction

Tendons connect muscle to bone; ligaments connect bone to bone. Skeletal muscles generate movement through actin–myosin interactions requiring ATP and calcium. Bones support, protect, store minerals, and contain marrow involved in blood-cell production.

Skin provides a barrier, sensation, and temperature regulation. Sweat evaporation helps remove heat. Innate defenses respond broadly; adaptive defenses are antigen-specific and can produce memory. B cells can become antibody-secreting plasma cells; T cells have several roles in cellular immunity and coordination. Vaccination builds adaptive immune memory; it is not a guarantee that exposure can never cause infection.

Sperm form in testes; egg cells develop in ovaries. Fertilization usually occurs in a uterine tube; implantation normally occurs in the uterus. Estrogen and progesterone help regulate reproductive tissues. FSH and LH participate in gamete production and the ovarian cycle.

Study systems as connected pathways: identify an input, the organ that changes it, an output, and a feedback response.

Cells, membranes, and energy

Prokaryotic cells lack a membrane-bound nucleus; eukaryotic cells have one. Both have DNA, ribosomes, and a plasma membrane. Ribosomes synthesize proteins; rough ER supports synthesis of many secreted/membrane proteins; Golgi modifies and sorts; lysosomes help break down material; mitochondria support aerobic ATP production.

Diffusion is net movement down a concentration gradient. Osmosis is water movement across a selectively permeable membrane. Active transport uses energy to move substances against a gradient. Facilitated diffusion uses proteins but moves down a gradient without directly spending ATP.

In a hypotonic environment, a red cell tends to gain water and may lyse; in a hypertonic environment it tends to lose water. Isotonic conditions produce no sustained net water shift.

Photosynthesis stores energy in chemical compounds. Cellular respiration releases usable energy and produces ATP; plants perform both. Glycolysis occurs in the cytosol; major aerobic stages occur in mitochondria.

Genetics, division, enzymes, and biological organization

DNA bases pair A–T and G–C; RNA uses U instead of T. Transcription makes RNA from a DNA template. Translation uses mRNA at ribosomes to make a polypeptide. Proteins’ structures support their functions.

Mitosis generally preserves chromosome number and produces two daughter cells. Meiosis reduces chromosome number and produces haploid cells with genetic variation. Crossing over and independent assortment contribute to variation.

For a simple completely dominant trait, Aa × Aa gives a genotype ratio of 1 AA : 2 Aa : 1 aa. Probability of aa is 1/4; dominant phenotype is 3/4 under those assumptions. Genotype is not the same as phenotype, and many real traits are not simple single-gene traits.

Enzymes speed reactions by lowering activation energy; they do not change the reaction’s equilibrium. Temperature and pH can affect activity and extreme conditions may disrupt shape. Biological organization proceeds cell → tissue → organ → organ system → organism.

Chemistry essentials

Protons are positive, neutrons uncharged, and electrons negative. Atomic number = protons. Mass number = protons + neutrons. Isotopes have the same proton count but different neutron counts. Ions differ in electron count; 11 protons and 10 electrons gives a +1 charge.

Covalent bonds share electrons; ionic attraction occurs between oppositely charged ions. Polar molecules have uneven charge distribution. Hydrogen bonding contributes to water’s properties and biomolecular interactions.

Balance chemical equations using coefficients; do not change compound subscripts. 2H₂ + O₂ → 2H₂O conserves each type of atom. In a closed system, ordinary chemical reactions conserve total mass.

pH below 7 is acidic and above 7 basic under standard introductory conditions. pH is logarithmic: a pH 3 solution has 100 times the hydrogen-ion concentration of pH 5. Melting and boiling are physical changes; rusting and combustion are chemical changes. Concentration compares solute with solution volume; track whether a problem specifies mass/volume, percent, or another unit.

Scientific reasoning and experimental design

Independent variable: manipulated factor. Dependent variable: measured response. Controlled variables: other conditions kept comparable. A comparison/control group helps determine what happens without the tested intervention.

A testable hypothesis makes a measurable prediction that observations could contradict. Random assignment helps balance preexisting group differences; random sampling concerns how participants are selected from a population. They solve different problems.

Replication tests reproducibility and reveals variability. Precision means repeated measurements cluster; accuracy means closeness to a true or accepted value. A tightly clustered but systematically wrong scale is precise but inaccurate.

Correlation alone does not establish causation. Consider confounding, selection bias, sample size, variability, measurement quality, and the uncertainty of estimates. A graph of two averages without sample sizes or variability is incomplete evidence. Separate the observation from the proposed explanation.

Practice: for every experiment, write “changed / measured / held similar / comparison / possible limitation.”

Sentence structure, agreement, and pronouns

An independent clause has a subject, a complete predicate, and a complete thought. A dependent clause introduced by “because” or “although” cannot usually stand alone. “Although the rain stopped” is a fragment; adding “the field remained muddy” makes a sentence.

Find the actual subject before choosing a verb. “Each of the students is ready”: each is singular; the phrase “of the students” does not change that.

Use pronouns with clear antecedents and appropriate agreement. “When Maya called Elena, she was at the library” is ambiguous. If Elena’s location matters, write “Elena was at the library when Maya called her.” Singular “they” is accepted in many contexts; avoid assuming that its use alone is an error.

Keep verb tenses consistent and use past perfect for an earlier past action when needed: “By the time we arrived, the office had closed.”

Punctuation, modifiers, parallelism, and spelling

A comma alone normally cannot join independent clauses. Fix “The class ended, the students left” with a period, semicolon, or comma plus a coordinating conjunction: “The class ended, and the students left.” A semicolon joins related independent clauses; a colon can introduce an explanation or list after a complete clause.

Use an apostrophe for possession: one nurse’s badge; several nurses’ lounge. “It’s” means it is/it has; “its” is possessive. “They’re” = they are; “their” = belonging to them; “there” = a place.

Place an opening modifier next to its doer: “Walking into the lab, Maya noticed the window,” not “Walking into the lab, the window was open.” Keep lists parallel: reading, writing, and calculating.

Proofread commonly confused words: affect/effect, then/than, lose/loose, accept/except. Learn tricky spellings in short retrieval drills, for example accommodation and necessary, instead of only rereading a list.

Purpose, audience, organization, and revision

Identify the audience and purpose before choosing tone. An application needs clear, professional language; a public handout should explain necessary technical terms. Formal does not mean wordy.

A focused thesis gives a manageable claim. Topic sentences introduce paragraph-level ideas; supporting details should directly develop them. Arrange material logically by sequence, comparison, cause/effect, or another appropriate structure. Use transitions that match the relationship: however for contrast, therefore for consequence, for example for illustration.

Revise ideas, structure, and clarity before proofreading punctuation and spelling. Replace vague descriptions with evidence: “temperature rose from 20°C to 25°C in five minutes” is more precise than “it changed a lot.”

Remove unnecessary words: “because” can replace “due to the fact that.” Choose active voice when it makes the actor and action clearer, while recognizing that passive voice can be appropriate when the actor is unknown or unimportant.

Vocabulary, word parts, and source use

Use word parts as clues, then confirm meaning from the sentence. Context can distinguish a common meaning from a specialized one. “Mitigate” means reduce severity, not necessarily eliminate.

Evaluate a source’s author, evidence, purpose, and relevant currency. Use the original study when possible, but assess its methods and limitations. Mark exact borrowed language as a quotation and cite it; paraphrased borrowed ideas also need attribution.

Last-pass check: read for meaning, then separately check sentence completeness, subject–verb agreement, pronouns, punctuation, spelling, and unnecessary repetition.