Math — algebra, geometry and number sense
Eighth-grade math is where algebra becomes the main event. Students solve multi-step equations, read slope from a graph, meet irrational numbers and put the Pythagorean theorem to work. This round moves from quick number sense to two questions that reward thinking over memory, including one about scaling that still catches out plenty of adults.
Q1.What is the square root of 144?Tap to reveal
Answer: 12
144 is a perfect square, the result of multiplying a whole number by itself, and it even has an old name of its own, a gross, meaning a dozen dozens.
Q2.Solve for x: 2x plus 5 equals 17.Tap to reveal
Answer: x equals 6
Undo the operations in reverse order, subtracting 5 before dividing by 2, which is the order of operations run backwards.
Q3.What does any nonzero number raised to the power of zero equal?Tap to reveal
Answer: 1
Each step down in the exponent divides by the base once more, so 10 squared is 100, 10 to the first is 10, and the next step down lands on 1.
Q4.What is the name for a polygon with eight sides?Tap to reveal
Answer: An octagon
The interior angles of any polygon add up to 180 degrees times the number of sides minus two, which gives 1,080 degrees for an octagon.
Q5.A right triangle has legs 3 and 4 units long. How long is the hypotenuse?Tap to reveal
Answer: 5 units
The Pythagorean theorem, a squared plus b squared equals c squared, works only for right triangles, and 3, 4, 5 is the smallest whole-number set that fits it.
Q6.Is the square root of 2 a rational or an irrational number?Tap to reveal
Answer: Irrational
Its decimal goes on forever without repeating, so it can never be written as a fraction of two whole numbers, something ancient Greek mathematicians had already proved.
Q7.How is 45,000 written in scientific notation?Tap to reveal
Answer: 4.5 times 10 to the 4th power
Scientific notation always leaves exactly one nonzero digit before the decimal point, which makes huge and tiny numbers easy to compare at a glance.
Q8.What is the slope of the line through the points (2, 1) and (4, 9)?Tap to reveal
Answer: 4
Slope is the change in y divided by the change in x, and a positive slope means the line climbs from left to right.
Q9.Solve the system: x plus y equals 10, and x minus y equals 4.Tap to reveal
Answer: x equals 7 and y equals 3
Adding the two equations makes y cancel out straight away, a shortcut called the elimination method.
Q10.If you double the length of each side of a square, what happens to its area?Tap to reveal
Answer: It becomes four times as large
Volume works the same way one power higher, so doubling the edge of a cube makes its volume eight times as large.
US history — the Constitution to Reconstruction
Most US eighth graders study the young republic: how the Constitution was built, how the nation grew westward, and how the long argument over slavery led to the Civil War and the rebuilding that followed. These questions stay with the documents, compromises, people and turning points that textbooks at this level focus on.
Q1.In which city was the US Constitution written in 1787?Tap to reveal
Answer: Philadelphia
The delegates met in the same building where the Declaration of Independence had been signed, known today as Independence Hall.
Q2.What are the first ten amendments to the Constitution called?Tap to reveal
Answer: The Bill of Rights
James Madison drafted them, and several states had agreed to ratify the Constitution only on the understanding that such protections would be added.
Q3.Which 1803 Supreme Court case established the court's power to strike down laws that break the Constitution?Tap to reveal
Answer: Marbury v. Madison
The power is called judicial review, and the Constitution itself never spells it out in words.
Q4.Which two men led the expedition President Thomas Jefferson sent west in 1804 to explore the Louisiana Territory?Tap to reveal
Answer: Meriwether Lewis and William Clark
A Shoshone woman named Sacagawea joined them as an interpreter, and her people provided the horses the group needed to cross the Rocky Mountains.
Q5.During which war did British troops burn the White House in 1814?Tap to reveal
Answer: The War of 1812
The Star-Spangled Banner was written during the same war, after Francis Scott Key watched the British bombard Fort McHenry in Baltimore.
Q6.Which 1820 agreement admitted Missouri as a slave state and Maine as a free state?Tap to reveal
Answer: The Missouri Compromise
It also drew a line at latitude 36 degrees 30 minutes across the rest of the Louisiana Territory, banning slavery north of it outside Missouri.
Q7.What was the network of secret routes and safe houses that helped enslaved people escape to freedom called?Tap to reveal
Answer: The Underground Railroad
Harriet Tubman escaped slavery in Maryland and then went back again and again to guide family members and others north.
Q8.In 1865, at which Virginia village did Robert E. Lee surrender to Ulysses S. Grant?Tap to reveal
Answer: Appomattox Court House
Grant let Confederate soldiers take their horses home for spring planting, and in 1869 he became the 18th president.
Q9.Which amendment to the Constitution abolished slavery in the United States?Tap to reveal
Answer: The 13th Amendment
It was ratified in December 1865, making abolition permanent across the whole country in a way the wartime Emancipation Proclamation could not.
Q10.Which federal agency was created in 1865 to help formerly enslaved people with food, schooling and legal protection?Tap to reveal
Answer: The Freedmen's Bureau
It helped found many schools and colleges, and Howard University in Washington is named after the general who ran it.
Physical science and chemistry
Physical science in eighth grade is about measuring the world: speed, force, energy and density, plus a first steady look at the periodic table and chemical reactions. The round starts with symbols and states of matter and ends with two questions that ask students to apply a law rather than simply name it.
Q1.What is the chemical symbol for sodium?Tap to reveal
Answer: Na
It comes from natrium, an older Latin-based name, which is also why potassium is K, from kalium.
Q2.What are the three common states of matter?Tap to reveal
Answer: Solid, liquid and gas
A fourth state, plasma, forms when a gas gets hot enough to strip electrons from its atoms, and most of the visible matter in stars is plasma.
Q3.What do we call the chart that arranges all known elements in order of atomic number?Tap to reveal
Answer: The periodic table
Dmitri Mendeleev left gaps in his 1869 table for elements nobody had found yet, and he correctly predicted what several of them would be like.
Q4.What is the metric (SI) unit used to measure force?Tap to reveal
Answer: The newton
One newton is roughly the weight of a small apple resting in your hand, which suits a unit named after the scientist in the famous apple story.
Q5.What is the formula for average speed?Tap to reveal
Answer: Distance divided by time
Velocity adds a direction to speed, so a car circling a track at a steady pace has a constant speed but a changing velocity.
Q6.Newton's third law says every action has an equal and opposite what?Tap to reveal
Answer: Reaction
It is how rockets fly in space, since the engine pushes gas backward and the gas pushes the rocket forward with no air needed to push against.
Q7.Which group of elements in the far right column of the periodic table rarely reacts with anything?Tap to reveal
Answer: The noble gases
Their outer shell of electrons is already full, which is why helium is safe in party balloons while hydrogen would burn.
Q8.What kind of energy is stored in a stretched rubber band or a book sitting on a high shelf?Tap to reveal
Answer: Potential energy
Once it is released, that stored energy turns into kinetic energy, the energy of motion.
Q9.A solid block has a mass of 20 grams and a volume of 10 cubic centimetres. What is its density?Tap to reveal
Answer: 2 grams per cubic centimetre
Water's density is about 1 gram per cubic centimetre, so any solid denser than that, including this block, sinks when dropped in.
Q10.Which scientific law says the total mass of the substances in a chemical reaction stays the same before and after?Tap to reveal
Answer: The law of conservation of mass
Antoine Lavoisier demonstrated it in the 1700s by weighing reactions inside sealed containers, so that no escaping gas could fool the scales.
English, literature and language
Eighth-grade English asks students to name the tools a writer is using and to handle grammar that goes beyond the basics, such as verbals and verb moods. This round mixes story terms, poetry and one great American author with the punctuation and word choices that show up in every piece of graded writing.
Q1.What is the main character of a story called?Tap to reveal
Answer: The protagonist
The character or force working against the protagonist is the antagonist, and it does not have to be a person at all.
Q2.Which part of speech describes a verb, as quickly does in she ran quickly?Tap to reveal
Answer: An adverb
Adverbs can also modify adjectives and other adverbs, the way very does in very tall.
Q3.What do we call a word that means the opposite of another word?Tap to reveal
Answer: An antonym
A homophone is something else again: it sounds the same as another word but has a different meaning, and often a different spelling, like pair and pear.
Q4.Which word correctly fills the gap in They left ___ backpacks on the bus: their, there or they're?Tap to reveal
Answer: Their
Expanding they're to they are shows at once when it does not fit, and there points to a place rather than an owner.
Q5.What do we call a hint early in a story about something that will happen later?Tap to reveal
Answer: Foreshadowing
Its opposite in time is the flashback, which jumps backward to show events that happened earlier.
Q6.What do we call a poem of exactly 14 lines, a form William Shakespeare wrote more than 150 times?Tap to reveal
Answer: A sonnet
A Shakespearean sonnet ends with a rhyming couplet, a pair of lines that often twists or sums up everything before it.
Q7.Which punctuation mark can join two closely related complete sentences without a word like and or but?Tap to reveal
Answer: A semicolon
A semicolon can also separate the items in a list when the items already contain commas, as in a list of cities paired with their states.
Q8.Which American writer wrote the poem The Raven?Tap to reveal
Answer: Edgar Allan Poe
Poe is widely credited with inventing the modern detective story, and his detective C. Auguste Dupin appeared decades before Sherlock Holmes.
Q9.What do we call an -ing verb form that works as a noun, as swimming does in Swimming is fun?Tap to reveal
Answer: A gerund
The same -ing form used as an adjective, as in the barking dog, is called a participle instead.
Q10.In the sentence If I were you, I would wait, which mood is the verb were in?Tap to reveal
Answer: The subjunctive mood
The subjunctive covers wishes and situations that are not real, which is why formal English keeps were even after I.
Frequently Asked Questions
Are these 8th grade trivia questions the right level for 13 and 14 year olds?
Yes. They follow standard eighth-grade content: linear equations, slope, exponents and the Pythagorean theorem; US history from 1787 to Reconstruction; force, energy, density and the periodic table; and grammar including verbals and the subjunctive mood. Each round runs from about four easy questions to two harder ones, so a mixed-ability group always has something everyone can answer.
How do I run this as a game in class?
Split the class into teams of three or four and allow about thirty seconds per question, a little longer for the math round. Have each team write its answer down before you reveal it, then read the explanation aloud, because that is where most of the learning happens. One round makes a ten-minute warm-up, and all four fill a full lesson or a review day.
Can I use these questions in class for free?
Yes. You can read them aloud, show them on a projector or copy them onto a worksheet for your own class, club or family at no cost. Every question was written specifically for this page rather than lifted from a textbook or test bank, and the print buttons at the top of the page give you a blank handout or a copy with the answer key.
Which question is the hardest for eighth graders?
Many eighth graders trip over the square whose side doubles. Instinct says the area doubles too, but it grows four times, and the same pattern one power higher, where volume grows eight times, explains why large animals need proportionally much thicker legs than small ones. In the English round, the subjunctive were in If I were you separates students who can hear that it sounds right from those who can say why.
Where can eighth graders play trivia online for free?
Right here. This page has a free quiz with no signup or download, and it runs on a phone, a laptop or a classroom projector. Trivio.NET also has science, history and geography quizzes, plus interactive map quizzes of the US states and the original 13 colonies that pair well with the US history round.
