Math Trivia Quiz
Pi, primes, Fibonacci and the Fields Medal: 15 math trivia questions to test your number sense.
What is the value of pi rounded to two decimal places?
Got a hunch? Pick the answer that feels right.
3.14
Pi, the ratio of a circle's circumference to its diameter, begins 3.14159 and continues forever without repeating, so 3.14 is the familiar two decimal approximation.
Pi Day is celebrated on March 14 (3/14), which is also Albert Einstein's birthday and the date Stephen Hawking died in 2018.
What is the only even prime number?
Got a hunch? Pick the answer that feels right.
Two
A prime number has exactly two factors, 1 and itself. Two qualifies, but every larger even number is divisible by 2, so no other even number can be prime.
Mathematicians have proved there are infinitely many primes, a result Euclid demonstrated more than 2,000 years ago.
How many degrees do the interior angles of any triangle add up to?
Got a hunch? Pick the answer that feels right.
180
In flat Euclidean geometry the three interior angles of every triangle sum to 180 degrees, whether the triangle is tiny or enormous, right-angled or scalene.
On a curved surface the rule breaks: a triangle drawn on a globe can have angles that add up to more than 180 degrees.
What is 15 percent of 200?
Got a hunch? Pick the answer that feels right.
30
Ten percent of 200 is 20 and five percent is 10, so 15 percent is 30. Splitting percentages into tens and fives is the quickest way to do tips and discounts in your head.
The percent sign evolved over centuries from the way Italian merchants abbreviated the phrase per cento, meaning per hundred, in their account books.
Which Greek mathematician's theorem relates the three sides of a right-angled triangle?
Got a hunch? Pick the answer that feels right.
Pythagoras
The Pythagorean theorem states that the square of the hypotenuse equals the sum of the squares of the other two sides, written as a squared plus b squared equals c squared.
Babylonian clay tablets show the relationship was known a thousand years before Pythagoras, though his school is credited with proving it.
In the Fibonacci sequence 1, 1, 2, 3, 5, 8, which number comes next?
Got a hunch? Pick the answer that feels right.
13
Each Fibonacci number is the sum of the two before it, so after 5 and 8 the next term is 13, followed by 21, 34 and 55.
Fibonacci numbers turn up in nature, from the spirals of sunflower seeds to the number of petals on many flowers.
Which number system, used by computers, has only the digits 0 and 1?
Got a hunch? Pick the answer that feels right.
Binary
Binary is a base two system in which each digit, or bit, represents a power of two, so the binary number 101 equals 4 plus 0 plus 1, or 5 in decimal.
The word bit was coined by statistician John Tukey in 1947 as a contraction of binary digit.
A googol is the number 1 followed by how many zeros?
Got a hunch? Pick the answer that feels right.
100
A googol is 10 to the power of 100, a 1 followed by 100 zeros, a number far larger than the estimated count of atoms in the observable universe.
The term was invented in 1920 by nine-year-old Milton Sirotta, nephew of mathematician Edward Kasner, and later inspired the name Google.
Which ancient Greek mathematician wrote Elements, the textbook that defined geometry for more than 2,000 years?
Got a hunch? Pick the answer that feels right.
Euclid
Euclid of Alexandria compiled Elements around 300 BC, building all of geometry from a handful of axioms, and it remained a standard textbook into the twentieth century.
Abraham Lincoln reportedly carried a copy of Euclid and studied it to sharpen his legal reasoning.
How many sides does a dodecagon have?
Got a hunch? Pick the answer that feels right.
12
The prefix dodeca comes from the Greek for twelve, so a dodecagon is a twelve-sided polygon, and the interior angles of a regular dodecagon each measure 150 degrees.
A dodecahedron, by contrast, is a three-dimensional solid with twelve pentagonal faces, and it is one of the five Platonic solids known since ancient Greece.
What is 7 factorial, written 7!?
Got a hunch? Pick the answer that feels right.
5,040
Seven factorial means 7 times 6 times 5 times 4 times 3 times 2 times 1, which works out to 5,040, the number of ways to arrange seven different objects in a row.
Factorials grow explosively: 10! is already over 3.6 million, and 52!, the number of ways to shuffle a deck of cards, has 68 digits.
What is the sum of all the whole numbers from 1 to 100, the problem a young Gauss famously solved in moments?
Got a hunch? Pick the answer that feels right.
5,050
Pairing the numbers from opposite ends gives 50 pairs that each add to 101 (1 plus 100, 2 plus 99 and so on), so the total is 50 times 101, which is 5,050.
The same pairing trick gives the general formula n times n plus 1 over 2 for the sum of the first n whole numbers.
What is the name for a number that equals the sum of its proper divisors, such as 6 and 28?
Got a hunch? Pick the answer that feels right.
Perfect number
A perfect number equals the sum of its divisors excluding itself: 6 equals 1 plus 2 plus 3, and 28 equals 1 plus 2 plus 4 plus 7 plus 14. The next ones are 496 and 8,128.
Nobody knows whether an odd perfect number exists, one of the oldest unsolved problems in mathematics.
Which award, given every four years to mathematicians under 40, is often called the Nobel Prize of mathematics?
Got a hunch? Pick the answer that feels right.
Fields Medal
The Fields Medal has been presented at the International Congress of Mathematicians since 1936, with the strict rule that recipients must be under 40 on 1 January of the award year.
Iranian mathematician Maryam Mirzakhani became the first woman to win the Fields Medal in 2014, for her work on the geometry of curved surfaces.
Which mathematician finally proved Fermat's Last Theorem in the 1990s, more than 350 years after it was proposed?
Got a hunch? Pick the answer that feels right.
Andrew Wiles
Andrew Wiles, a British mathematician at Princeton, announced his proof in 1993, repaired a gap with Richard Taylor, and published the final version in 1995 after seven years of near-secret work.
Fermat scribbled in a margin in 1637 that he had a marvellous proof but no room to write it down, a claim almost nobody now believes.
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All Science quizzes →About the Math Trivia Quiz
Pi has been calculated to more than 100 trillion digits, yet NASA needs only about 15 of them to steer spacecraft. A googol is a 1 followed by 100 zeros, and the young Carl Friedrich Gauss is said to have added the numbers from 1 to 100 in seconds by spotting a pattern his teacher had missed.
These 15 questions mix mental arithmetic, geometry and number theory with the stories of Pythagoras, Euclid, Archimedes and Andrew Wiles. The early ones are gettable by anyone who remembers school maths, while the last few will reward true number lovers. It suits quiz night regulars, students and anyone who secretly enjoys a sum.
You will find 15 multiple choice questions here, each with four options. Difficulty: Medium. Most people finish in about 6 minutes, and every answer comes with a short explanation and one extra fact worth keeping.
How to play
Read the question and pick one of the four answers. The correct answer is revealed straight away with a short explanation, then press Next question to keep going. At the end you get your score out of 15 and a full review of your round. Play again any time and the questions arrive in a fresh order. There is no timer and no account.
Good to know before you play
Do I need a calculator for this math trivia quiz?
No. The arithmetic can be done in your head, and most questions test knowledge of famous numbers, shapes and mathematicians rather than long calculations.
What is the only even prime number?
Two is the only even prime, because every other even number can be divided by 2 and therefore has more than two factors.
Who won the Fields Medal and why is it famous?
The Fields Medal is awarded every four years to up to four mathematicians under 40 and is often described as the Nobel Prize of mathematics.
Answer key: all 15 questions with explanations
- What is the value of pi rounded to two decimal places?
3.14 Pi, the ratio of a circle's circumference to its diameter, begins 3.14159 and continues forever without repeating, so 3.14 is the familiar two decimal approximation. Pi Day is celebrated on March 14 (3/14), which is also Albert Einstein's birthday and the date Stephen Hawking died in 2018. - What is the only even prime number?
Two A prime number has exactly two factors, 1 and itself. Two qualifies, but every larger even number is divisible by 2, so no other even number can be prime. Mathematicians have proved there are infinitely many primes, a result Euclid demonstrated more than 2,000 years ago. - How many degrees do the interior angles of any triangle add up to?
180 In flat Euclidean geometry the three interior angles of every triangle sum to 180 degrees, whether the triangle is tiny or enormous, right-angled or scalene. On a curved surface the rule breaks: a triangle drawn on a globe can have angles that add up to more than 180 degrees. - What is 15 percent of 200?
30 Ten percent of 200 is 20 and five percent is 10, so 15 percent is 30. Splitting percentages into tens and fives is the quickest way to do tips and discounts in your head. The percent sign evolved over centuries from the way Italian merchants abbreviated the phrase per cento, meaning per hundred, in their account books. - Which Greek mathematician's theorem relates the three sides of a right-angled triangle?
Pythagoras The Pythagorean theorem states that the square of the hypotenuse equals the sum of the squares of the other two sides, written as a squared plus b squared equals c squared. Babylonian clay tablets show the relationship was known a thousand years before Pythagoras, though his school is credited with proving it. - In the Fibonacci sequence 1, 1, 2, 3, 5, 8, which number comes next?
13 Each Fibonacci number is the sum of the two before it, so after 5 and 8 the next term is 13, followed by 21, 34 and 55. Fibonacci numbers turn up in nature, from the spirals of sunflower seeds to the number of petals on many flowers. - Which number system, used by computers, has only the digits 0 and 1?
Binary Binary is a base two system in which each digit, or bit, represents a power of two, so the binary number 101 equals 4 plus 0 plus 1, or 5 in decimal. The word bit was coined by statistician John Tukey in 1947 as a contraction of binary digit. - A googol is the number 1 followed by how many zeros?
100 A googol is 10 to the power of 100, a 1 followed by 100 zeros, a number far larger than the estimated count of atoms in the observable universe. The term was invented in 1920 by nine-year-old Milton Sirotta, nephew of mathematician Edward Kasner, and later inspired the name Google. - Which ancient Greek mathematician wrote Elements, the textbook that defined geometry for more than 2,000 years?
Euclid Euclid of Alexandria compiled Elements around 300 BC, building all of geometry from a handful of axioms, and it remained a standard textbook into the twentieth century. Abraham Lincoln reportedly carried a copy of Euclid and studied it to sharpen his legal reasoning. - How many sides does a dodecagon have?
12 The prefix dodeca comes from the Greek for twelve, so a dodecagon is a twelve-sided polygon, and the interior angles of a regular dodecagon each measure 150 degrees. A dodecahedron, by contrast, is a three-dimensional solid with twelve pentagonal faces, and it is one of the five Platonic solids known since ancient Greece. - What is 7 factorial, written 7!?
5,040 Seven factorial means 7 times 6 times 5 times 4 times 3 times 2 times 1, which works out to 5,040, the number of ways to arrange seven different objects in a row. Factorials grow explosively: 10! is already over 3.6 million, and 52!, the number of ways to shuffle a deck of cards, has 68 digits. - What is the sum of all the whole numbers from 1 to 100, the problem a young Gauss famously solved in moments?
5,050 Pairing the numbers from opposite ends gives 50 pairs that each add to 101 (1 plus 100, 2 plus 99 and so on), so the total is 50 times 101, which is 5,050. The same pairing trick gives the general formula n times n plus 1 over 2 for the sum of the first n whole numbers. - What is the name for a number that equals the sum of its proper divisors, such as 6 and 28?
Perfect number A perfect number equals the sum of its divisors excluding itself: 6 equals 1 plus 2 plus 3, and 28 equals 1 plus 2 plus 4 plus 7 plus 14. The next ones are 496 and 8,128. Nobody knows whether an odd perfect number exists, one of the oldest unsolved problems in mathematics. - Which award, given every four years to mathematicians under 40, is often called the Nobel Prize of mathematics?
Fields Medal The Fields Medal has been presented at the International Congress of Mathematicians since 1936, with the strict rule that recipients must be under 40 on 1 January of the award year. Iranian mathematician Maryam Mirzakhani became the first woman to win the Fields Medal in 2014, for her work on the geometry of curved surfaces. - Which mathematician finally proved Fermat's Last Theorem in the 1990s, more than 350 years after it was proposed?
Andrew Wiles Andrew Wiles, a British mathematician at Princeton, announced his proof in 1993, repaired a gap with Richard Taylor, and published the final version in 1995 after seven years of near-secret work. Fermat scribbled in a margin in 1637 that he had a marvellous proof but no room to write it down, a claim almost nobody now believes.
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