- Main idea
- The central point a passage conveys — what the whole text is mostly about.
- Supporting detail
- A fact, example, statistic, or reason that explains or develops the main idea.
- Author's purpose
- The reason a text was written — to inform, persuade, entertain, or explain.
- Tone
- The author's attitude toward the subject, shown through word choice.
- Mood
- The feeling or atmosphere a text creates in the reader.
- Inference
- A logical conclusion drawn from text evidence plus reasoning — not stated outright.
- Extended Response
- The 45-minute RLA essay analyzing which of two passages is better supported by evidence.
- Claim
- A debatable statement an author argues for; your essay must state a clear claim.
- Evidence
- The facts, examples, and reasoning used to support a claim.
- Counterargument
- An opposing view that a writer acknowledges and then responds to.
- Denotation
- The literal, dictionary definition of a word.
- Connotation
- The emotional or implied meaning of a word beyond its literal definition.
- Topic sentence
- The sentence (often first) that states a paragraph's main idea.
- Thesis statement
- A sentence stating the main argument or claim of an essay.
- Theme
- The underlying message or insight about life in a literary work.
- Summary
- A brief restatement of a text's main points in your own words.
- Paraphrase
- Restating a specific passage in your own words, keeping the meaning.
- Context clues
- Hints in surrounding text that help you figure out an unfamiliar word's meaning.
- Bias
- A one-sided or prejudiced view that can weaken an argument's reliability.
- Fact vs. opinion
- A fact can be proven true; an opinion is a personal belief or judgment.
- Persuasive text
- Writing meant to convince the reader of a position.
- Informational text
- Writing meant to explain or inform; ~75% of GED RLA passages are informational.
- Literary text
- Fiction, drama, or poetry; ~25% of GED RLA passages are literary.
- Cause and effect
- A text structure showing how one event leads to another.
- Compare and contrast
- A text structure examining similarities and differences.
- Sequence
- A text structure presenting events or steps in order.
- Problem and solution
- A text structure that presents an issue and a way to resolve it.
- Point of view
- The perspective from which a text is told (first person, third person, etc.).
- Logical fallacy
- A flaw in reasoning that weakens an argument (e.g., hasty generalization).
- Rhetoric
- The art of persuasion through language; appeals to logic, emotion, and credibility.
- Subject-verb agreement
- A singular subject takes a singular verb; a plural subject a plural verb.
- Verb tense
- Keep tense consistent unless the time frame actually changes.
- Pronoun agreement
- A pronoun must match its noun in number and have a clear referent.
- Parallel structure
- Items in a list or comparison share the same grammatical form.
- Run-on sentence
- Two or more complete sentences joined without proper punctuation or conjunction.
- Sentence fragment
- An incomplete sentence missing a subject, verb, or complete thought.
- Comma splice
- Two independent clauses joined by only a comma — an error.
- Apostrophe
- Shows possession or contraction — not plurals.
- Homophones
- Words that sound alike but differ in meaning/spelling (their/there/they're).
- Modifier
- A word or phrase describing another; misplaced modifiers cause confusion.
- Transition words
- Words that connect ideas (however, therefore, in addition).
- Active voice
- The subject performs the action; usually clearer than passive voice.
- Conclusion (essay)
- The final paragraph that restates the claim and ties the argument together.
- Synthesis
- Combining ideas from multiple sources into a coherent whole.
- Slope
- Rise over run: (y₂ − y₁)/(x₂ − x₁); the m in y = mx + b.
- Y-intercept
- Where a line crosses the y-axis (x = 0); the b in y = mx + b.
- Slope-intercept form
- y = mx + b, where m is the slope and b is the y-intercept.
- Order of operations (PEMDAS)
- Parentheses, Exponents, Multiply/Divide (left→right), Add/Subtract (left→right).
- Linear equation
- An equation whose graph is a straight line; variables to the first power.
- Quadratic equation
- ax² + bx + c = 0; its graph is a parabola; solve by factoring or formula.
- Quadratic formula
- x = (−b ± √(b² − 4ac)) / (2a) — provided on the GED formula sheet.
- Ratio
- A comparison of two quantities by division, e.g. 3:4.
- Proportion
- Two equal ratios; solve by cross-multiplying.
- Percent
- A part per hundred; convert to a decimal by dividing by 100 (25% = 0.25).
- Percent of a number
- Convert the percent to a decimal and multiply: 20% of 80 = 0.20 × 80 = 16.
- Percent change
- (new − old) ÷ old × 100.
- Mean (average)
- Add all values, then divide by how many there are.
- Median
- The middle value of a data set arranged in order.
- Mode
- The value that appears most often in a data set.
- Range
- The highest value minus the lowest value.
- Probability
- Favorable outcomes ÷ total outcomes; a number from 0 to 1.
- Integer
- A whole number and its negatives: …, −2, −1, 0, 1, 2, …
- Absolute value
- A number's distance from zero; always non-negative. |−5| = 5.
- Exponent
- Shows repeated multiplication: 2³ = 2 × 2 × 2 = 8.
- Square root
- A value that, multiplied by itself, gives the number. √16 = 4.
- Greatest common factor
- The largest number that divides two numbers evenly.
- Least common multiple
- The smallest number both numbers divide into evenly.
- Adding fractions
- Use a common denominator, add the numerators, keep the denominator.
- Multiplying fractions
- Multiply numerators together and denominators together.
- Dividing fractions
- Multiply by the reciprocal of the second fraction (flip and multiply).
- Improper fraction
- A fraction whose numerator is ≥ its denominator, e.g. 7/4.
- Mixed number
- A whole number plus a fraction, e.g. 1¾.
- Rectangle area
- Area = length × width.
- Triangle area
- Area = ½ × base × height.
- Circle area
- Area = πr², where r is the radius.
- Circumference
- The distance around a circle: 2πr or πd.
- Rectangular solid volume
- Volume = length × width × height.
- Cylinder volume
- Volume = πr²h.
- Pythagorean theorem
- a² + b² = c² for the sides of a right triangle.
- Perimeter
- The total distance around a 2-D shape (add all sides).
- Function
- A rule giving each input exactly one output; f(x) is the output for input x.
- Inequality
- Compares values with <, >, ≤, or ≥; flip the sign when ×/÷ by a negative.
- Coordinate plane
- A grid of x (horizontal) and y (vertical) axes meeting at the origin (0,0).
- Distance formula (rate)
- Distance = rate × time (d = rt).
- Simple interest
- I = Prt — principal × rate × time.
- Variable
- A symbol (like x) standing for an unknown number.
- Coefficient
- The number multiplying a variable, e.g. 3 in 3x.
- Like terms
- Terms with the same variable part; only like terms can be combined.
- Solving for a variable
- Use inverse operations to isolate the variable on one side.
- Scientific notation
- A number written as a × 10ⁿ, e.g. 4.5 × 10³ = 4500.
- Weighted average
- An average where some values count more than others, by their weights.
- Photosynthesis
- Plants use sunlight, CO₂, and water to make glucose and oxygen in chloroplasts.
- Cellular respiration
- Cells break down glucose to release usable energy (roughly the reverse of photosynthesis).
- Hypothesis
- A testable, falsifiable proposed explanation, often an 'if…then…' prediction.
- Independent variable
- The variable the experimenter deliberately changes.
- Dependent variable
- The variable measured to see if it responds to the independent variable.
- Controlled variable
- A factor kept constant so an experiment is a fair test.
- Scientific method
- Observe, hypothesize, experiment, analyze data, and conclude.
- Cell
- The basic unit of life; plant cells have walls and chloroplasts, animal cells don't.
- Nucleus
- The cell organelle that contains DNA and directs cell activity.
- Mitochondria
- The organelle that produces energy (ATP) — the cell's 'powerhouse.'
- DNA
- The molecule that carries genetic instructions for traits.
- Gene
- A segment of DNA that codes for a specific trait.
- Dominant trait
- A trait that masks a recessive trait when both alleles are present.
- Recessive trait
- A trait expressed only when both alleles are recessive.
- Punnett square
- A grid used to predict the probability of offspring traits.
- Mitosis
- Cell division producing two identical cells for growth and repair.
- Meiosis
- Cell division producing sex cells (gametes) with half the chromosomes.
- Natural selection
- Better-adapted organisms survive and reproduce more — the engine of evolution.
- Evolution
- The change in inherited traits of a population over generations.
- Ecosystem
- A community of living organisms interacting with their non-living environment.
- Food chain
- A sequence showing energy flow as one organism eats another.
- Producer
- An organism (e.g. a plant) that makes its own food via photosynthesis.
- Consumer
- An organism that eats other organisms for energy.
- Decomposer
- An organism that breaks down dead matter, recycling nutrients.
- Homeostasis
- The maintenance of a stable internal environment in an organism.
- Atom
- The basic unit of matter, made of protons, neutrons, and electrons.
- Proton
- A positively charged particle in an atom's nucleus.
- Neutron
- A neutral (no-charge) particle in an atom's nucleus.
- Electron
- A negatively charged particle orbiting the atom's nucleus.
- Element
- A pure substance made of one type of atom; organized on the periodic table.
- Molecule
- Two or more atoms bonded together, e.g. H₂O.
- Physical change
- A change in form or state that doesn't create a new substance (e.g. melting).
- Chemical change
- A change that forms a new substance (e.g. burning, rusting).
- Conservation of mass
- Matter is neither created nor destroyed in a chemical reaction.
- States of matter
- Solid, liquid, and gas (and plasma); changes of state are physical changes.
- Newton's second law
- Force = mass × acceleration (F = ma).
- Kinetic energy
- The energy of motion.
- Potential energy
- Stored energy due to position or arrangement.
- Conservation of energy
- Energy is never created or destroyed — only transformed.
- Work
- Force applied over a distance: Work = force × distance.
- Water cycle
- Evaporation, condensation, precipitation, and collection/runoff of water.
- Weather vs. climate
- Weather is short-term; climate is the long-term average of conditions.
- Greenhouse effect
- Atmospheric gases trap heat; extra gases intensify warming.
- Plate tectonics
- Earth's crust is broken into moving plates that cause quakes and mountains.
- Solar system
- The Sun and the planets and bodies that orbit it; Earth's tilt causes seasons.
- Renewable resource
- A resource that replenishes naturally (e.g. solar, wind).
- Three branches of government
- Legislative (makes laws), Executive (enforces), Judicial (interprets).
- Legislative branch
- Congress — the Senate and House — which makes laws.
- Executive branch
- The President and federal agencies, which enforce laws.
- Judicial branch
- The Supreme Court and federal courts, which interpret laws.
- Separation of powers
- Dividing government authority among three branches.
- Checks and balances
- Each branch can limit the powers of the others.
- Judicial review
- The power of courts to declare a law or action unconstitutional.
- Constitution
- The supreme law of the United States, establishing the government's framework.
- Bill of Rights
- The first 10 amendments to the Constitution, guaranteeing basic rights.
- Amendment
- A formal change or addition to the Constitution; there are 27.
- Federalism
- The sharing of power between national and state governments.
- Democracy
- Government in which power comes from the people, often via elected representatives.
- Republic
- A government in which citizens elect representatives to make decisions.
- How a bill becomes law
- Introduced → committee → passed by both chambers → signed or vetoed by the President.
- Veto
- The President's power to reject a bill; Congress can override with a 2/3 vote.
- Electoral College
- The body that formally elects the U.S. President based on state electors.
- Declaration of Independence
- The 1776 document declaring the colonies' independence and natural rights.
- Constitutional Convention
- The 1787 meeting that wrote the U.S. Constitution.
- Civil War
- The 1861–1865 war over slavery and union; led to slavery's end.
- Reconstruction
- The post–Civil War era; 13th, 14th, and 15th Amendments expanded rights.
- 13th Amendment
- Abolished slavery in the United States.
- Civil Rights Movement
- The 1950s–60s struggle that ended legal segregation and expanded equal rights.
- Industrial Revolution
- A period of rapid industrial growth that transformed the economy.
- World War II
- The 1939–1945 global war; reshaped the U.S. role in the world.
- Cold War
- The post-WWII rivalry between the U.S. and the Soviet Union.
- Manifest Destiny
- The 19th-century belief that the U.S. was destined to expand westward.
- Supply and demand
- Price settles where the quantity supplied equals the quantity demanded.
- Scarcity
- Limited resources versus unlimited wants — the core economic problem.
- Equilibrium price
- The price where supply and demand are equal.
- Gross domestic product
- The total value of goods and services a country produces (GDP).
- Inflation
- A general rise in prices that lowers money's purchasing power.
- Recession
- A significant, widespread decline in economic activity.
- Microeconomics
- The study of individual consumers, firms, and markets.
- Macroeconomics
- The study of the whole economy — GDP, inflation, unemployment.
- Opportunity cost
- The value of the next-best alternative given up when making a choice.
- Capitalism
- An economic system based on private ownership and market competition.
- Tax
- A required payment to government used to fund public services.
- Map legend
- The key explaining a map's symbols, colors, and scale.
- Map scale
- Shows the ratio of map distance to real-world distance.
- Latitude and longitude
- Coordinates locating any point on Earth (north-south, east-west).
- Migration
- The movement of people from one place to another, often for resources or safety.
- Urbanization
- The growth of cities as people move from rural to urban areas.
- Globalization
- The increasing connection of economies and cultures worldwide.
- Primary source
- A firsthand account or original document from the time studied.
- Secondary source
- A later interpretation or analysis of primary sources.
- Civic responsibility
- A duty of citizens, such as voting, paying taxes, and obeying laws.
- Argument
- A claim supported by reasons and evidence, intended to persuade.
- Rebuttal
- A response that refutes an opposing argument.
- Audience
- The intended readers a text is written for, which shapes its style.
- Implicit meaning
- Meaning suggested or implied rather than directly stated.
- Explicit meaning
- Meaning stated directly and clearly in the text.
- Figurative language
- Language that goes beyond literal meaning (metaphor, simile, etc.).
- Metaphor
- A comparison stating one thing IS another (e.g. 'time is money').
- Simile
- A comparison using 'like' or 'as' (e.g. 'brave as a lion').
- Idiom
- A phrase whose meaning differs from its literal words (e.g. 'break the ice').
- Diction
- An author's specific word choice, which affects tone and meaning.
- Coherence
- Logical, smooth flow of ideas in writing.
- Conjunction
- A word that joins words or clauses (and, but, or, because).
- Independent clause
- A group of words with a subject and verb that can stand alone.
- Dependent clause
- A clause that cannot stand alone as a complete sentence.
- Capitalization
- Begin sentences and proper nouns with capital letters.
- Colon
- Introduces a list, explanation, or quotation after a complete sentence.
- Semicolon
- Joins two closely related independent clauses without a conjunction.
- Redundancy
- Needless repetition of ideas or words; cut it for clarity.
- Concise writing
- Expressing ideas clearly in as few words as needed.
- Quotation
- Another's exact words, set off by quotation marks and cited.
- Mean vs. median
- Mean is the average; median is the middle value (better with outliers).
- Outlier
- A data value much higher or lower than the rest.
- Estimate
- An approximate answer used to check reasonableness.
- Rounding
- Adjusting a number to a nearby value at a given place.
- Decimal place value
- Tenths, hundredths, thousandths to the right of the decimal point.
- Negative number rules
- Two negatives multiplied give a positive; a negative ÷ positive is negative.
- Distributive property
- a(b + c) = ab + ac.
- Combining like terms
- Add or subtract terms with the same variable: 3x + 2x = 5x.
- Factoring
- Writing an expression as a product, e.g. x² + 5x = x(x + 5).
- FOIL
- Multiply two binomials: First, Outer, Inner, Last terms.
- System of equations
- Two or more equations solved together for shared variables.
- Parallel lines
- Lines with equal slopes that never intersect.
- Perpendicular lines
- Lines whose slopes are negative reciprocals; they meet at 90°.
- Midpoint
- The point halfway between two points: average the x's and the y's.
- Surface area
- The total area of all the faces of a 3-D solid.
- Volume
- The space inside a 3-D solid, measured in cubic units.
- Diameter vs. radius
- The diameter is twice the radius; the radius is half the diameter.
- Pi (π)
- The ratio of a circle's circumference to its diameter, about 3.14.
- Unit rate
- A ratio comparing a quantity to one unit (e.g. miles per hour).
- Cross-multiplication
- To solve a/b = c/d, set ad = bc.
- Combination vs. permutation
- Combinations ignore order; permutations count order.
- Mean calculation example
- Mean of 4, 8, 10 = (4 + 8 + 10) ÷ 3 = 22 ÷ 3 ≈ 7.3.
- Chloroplast
- The plant organelle where photosynthesis occurs; contains chlorophyll.
- Chlorophyll
- The green pigment that captures light energy for photosynthesis.
- ATP
- Adenosine triphosphate — the molecule cells use to store and transfer energy.
- Chromosome
- A structure of coiled DNA carrying genes.
- Allele
- One of the alternative versions of a gene.
- Genotype
- An organism's genetic makeup (the alleles it carries).
- Phenotype
- An organism's observable traits, produced by genotype and environment.
- Adaptation
- A trait that improves an organism's survival in its environment.
- Biodiversity
- The variety of life in an ecosystem; greater diversity aids stability.
- Carrying capacity
- The maximum population an environment can sustain.
- Predator and prey
- A predator hunts and eats prey; their populations affect each other.
- Carbon cycle
- The movement of carbon through the atmosphere, organisms, and Earth.
- Periodic table
- A chart organizing elements by atomic number and properties.
- Compound
- A substance made of two or more elements chemically bonded.
- Mixture
- A physical combination of substances that keep their own properties.
- Acid vs. base
- Acids have a low pH (<7); bases have a high pH (>7); 7 is neutral.
- Density
- Mass per unit volume: density = mass ÷ volume.
- Velocity
- Speed in a given direction.
- Acceleration
- The rate of change of velocity over time.
- Gravity
- The force that attracts objects with mass toward each other.
- Friction
- A force opposing motion between surfaces in contact.
- Wave
- A disturbance that transfers energy; described by wavelength and frequency.
- Heat transfer
- Energy moves by conduction, convection, or radiation.
- Erosion
- The wearing away and transport of rock and soil by water, wind, or ice.
- Fossil
- Preserved remains or traces of past life, evidence of evolution and Earth's age.
- Magna Carta
- A 1215 English document limiting the king's power; an early rule-of-law model.
- Articles of Confederation
- The first U.S. governing document; too weak, replaced by the Constitution.
- Preamble
- The Constitution's introduction stating its purposes ('We the People…').
- Due process
- The legal requirement that the state respect a person's legal rights.
- Suffrage
- The right to vote.
- 19th Amendment
- Gave women the right to vote (1920).
- Political party
- An organized group that seeks to win elections and influence policy.
- Executive order
- A directive from the President that manages the federal government.
- Impeachment
- The process of formally charging a government official with misconduct.
- Monarchy
- A government ruled by a king or queen.
- Dictatorship
- A government in which one ruler holds absolute power.
- Boston Tea Party
- A 1773 protest against British taxes, fueling the Revolution.
- Emancipation Proclamation
- Lincoln's 1863 order freeing enslaved people in rebel states.
- Great Depression
- The severe 1930s economic downturn worldwide.
- New Deal
- FDR's 1930s programs to fight the Great Depression.
- Demand curve
- A graph showing demand falls as price rises (downward sloping).
- Supply curve
- A graph showing supply rises as price rises (upward sloping).
- Profit
- Revenue minus costs; the goal of a business in a market economy.
- Budget
- A plan for income and spending over a period of time.
- Credit and debt
- Borrowing money to be repaid, usually with interest.
- Tariff
- A tax on imported goods.
- Climate region
- An area defined by long-term temperature and precipitation patterns.
- Natural resource
- A material from nature used by people (water, oil, timber).
- Continent
- One of Earth's seven large landmasses.
- Time zone
- A region using the same standard time, set by longitude.
- Editing
- Revising a passage to fix grammar, usage, and clarity.
- Sensory detail
- Description appealing to sight, sound, touch, taste, or smell.
- Chronological order
- Arranging events in the time order they occurred.
- Plagiarism
- Using another's words or ideas without credit.
- Coordinate point
- An ordered pair (x, y) locating a spot on the plane.
- Equation vs. expression
- An equation has an equals sign; an expression does not.
- Mixed operations word problem
- Translate the words into one equation, then solve step by step.
- Reciprocal
- The flip of a fraction; a/b becomes b/a. The reciprocal of 3 is 1/3.
- Osmosis
- The movement of water across a membrane toward higher solute concentration.
- Cell membrane
- The boundary controlling what enters and leaves a cell.
- Newton’s first law
- An object stays at rest or in motion unless acted on by a net force (inertia).
- Conductor vs. insulator
- A conductor lets heat/electricity flow easily; an insulator resists it.
- Bias in sources
- A one-sided viewpoint that can distort a historical or news source.
- Cause of WWI
- Tensions, alliances, and the assassination of Archduke Franz Ferdinand.
- Free market
- An economy where prices are set by supply and demand, not government.
- GDP per capita
- A country’s GDP divided by its population; a rough living-standard measure.
