160 free 9th Grade trivia questions with answers — trivia quiz, new questions added Aug 2026.
This 9th grade trivia quiz is built around what a typical freshman actually studies: Algebra I (slope, linear and quadratic equations, primes, the Pythagorean theorem), Biology (cells, photosynthesis, mitosis, DNA, Mendel and Darwin, food chains), World History (Mesopotamia and Egypt through Greece, Rome, the Renaissance, the French Revolution, the Industrial Revolution and World War I) and English (Romeo and Juliet, To Kill a Mockingbird, Of Mice and Men, The Odyssey, Lord of the Flies, Animal Farm and The Great Gatsby). If you want the wider school experience rather than the syllabus, our high school trivia quiz covers that. The easy questions are the ones any 14-year-old should get: what a prime number is, which family Juliet belongs to, who wrote On the Origin of Species. From there it climbs to the things that separate an A from a B: the year Mendel published, why the Bastille held only seven prisoners, what the discriminant tells you, which emperor moved the capital to Byzantium. Teachers can use it as a review game; parents can use it to check whether they still remember freshman year. Every answer was checked against the encyclopaedia entry for the topic before publishing, and the sentence that supports it is stored with each question.
30 of 160 questions with answers and explanations. Play the quiz
Q 01What do we call a natural number greater than 1 that is not a product of two smaller numbers?
Prime
The primes are the building blocks of every whole number, which is why 1 is left out of the club.
Q 02Which letter usually stands for the slope of a line in the equation y = mx + b?
m
Nobody is sure why m was chosen; it first shows up in an 1844 English textbook.
Q 03Slope is defined as the ratio of which two things?
Rise to run
A steeper line has a bigger absolute slope; a horizontal line has slope zero.
Q 04What is the maximum number of solutions a quadratic equation can have?
Two
The graph is a parabola, and a parabola can cross the x-axis at most twice.
Q 05In ax² + bx + c = 0, what is the name given to c?
Constant coefficient
a is the quadratic coefficient and b the linear one; if a were zero the equation would just be linear.
Q 06Which method is used to derive the quadratic formula?
Completing the square
You rewrite ax² + bx + c as a perfect square plus a constant, then take a square root.
Q 07The Pythagorean theorem relates the three sides of which kind of triangle?
Right
The side opposite the right angle, the hypotenuse, is the one that gets squared alone.
Q 08What is the name for the side of a right triangle opposite the right angle?
Hypotenuse
It is always the longest side, which is why c² has to equal a² + b².
Q 09Around what year was Pythagoras born?
570 BC
Babylonian scribes were using the same rule more than a thousand years before he was born.
Q 10Which civilisation used the Pythagorean rule over a thousand years before Pythagoras?
Babylonians
An Egyptian papyrus from about 1800 BC also has a 6:8:10 problem, but it never mentions a triangle.
Q 11The word 'algebra' comes from which language?
Arabic
Al-jabr originally referred to setting broken bones before it meant balancing equations.
Q 12Which 9th-century Persian mathematician gave algebra its name?
Al-Khwarizmi
His name, Latinised, is also where the word algorithm comes from.
Q 13Which 3rd-century Greek wrote the Arithmetica, an early treatment of solving equations?
Diophantus
His name survives in Diophantine equations, where only whole-number solutions count.
Q 14Who proved around 300 BC that there are infinitely many primes?
Q 21Which organelles provide energy for cell functions?
Mitochondria
Plants have both mitochondria and chloroplasts, and use the second to make sugars.
Q 22Bacteria and archaea belong to which broad group of single-celled organisms?
Prokaryotes
Their DNA sits in a region called the nucleoid rather than inside a membrane.
Q 23What is the largest membrane-bound organelle in a eukaryotic cell?
Nucleus
It holds the cell's chromosomes inside a double membrane called the nuclear envelope.
Q 24What gas do plants release as a by-product of photosynthesis?
Euclid
The same Elements also proves that every whole number factors into primes in only one way.
Q 15What is the only even prime number?
2
Every other even number is divisible by 2, so every other prime is odd.
Q 16Which ancient Greek's 'sieve' is still used to list prime numbers?
Eratosthenes
You write out the numbers and cross off every multiple of each prime you find.
Q 17The solutions of a linear equation in two variables form what shape on a graph?
A straight line
Every line in the plane can be written as ax + by + c = 0 and vice versa.
Q 18Which form of algebra, taught in schools, uses variables to stand for unspecified values?
Elementary
Abstract algebra, with its groups, rings and fields, comes much later.
Q 19What is the basic structural and functional unit of all living things?
The cell
The name comes from the Latin cellula, a small room.
Q 20Who discovered cells in 1665, naming them after rooms in a monastery?
Robert Hooke
He was looking at slices of cork under an early microscope.
Oxygen
It comes from splitting water molecules, not from the carbon dioxide.
Q 25Which pigment in chloroplasts absorbs red and blue light and reflects green?
Chlorophyll
Leaves look green precisely because green is the colour the pigment throws back.
Q 26What is the name of the light-independent reactions that build sugars in plants?
Calvin cycle
They use the ATP and NADPH made in the light-dependent stage to fix carbon dioxide.
Q 27Which two raw materials do photoautotrophs use to make food with light energy?
Carbon dioxide and water
The sugar they make is later burned again in cellular respiration.
Q 28What molecule stores the chemical energy produced by cellular respiration?
ATP
Textbooks say up to 38 ATP per glucose; the real yield is closer to 30.
Q 29Which first stage of cellular respiration takes place in the cytosol of every living cell?
Glycolysis
The name literally means sugar splitting, and it works with or without oxygen.
Q 30How many ATP molecules per glucose do biology textbooks often say respiration makes?
38
Leaky membranes and transport costs mean the real figure is closer to 29 or 30.