Math · 2
What operation does the Collatz Conjecture instruct you to perform on an odd number?
Answer
Multiply by 3 and add 1
The Collatz Conjecture defines two rules: if a number is even, divide it by 2; if it is odd, multiply by 3 and add 1. Repeating these steps on any positive integer is conjectured to eventually reach 1, though this has never been proven.
💡 Did you know?
The Collatz Conjecture—propose any number, halve if even or triple-and-add-one if odd, repeat—remains unsolved despite its child-simple description.
Other options people guess
- Divide by 3 and subtract 1
- Multiply by 2 and add 3
- Add 1 and divide by 3
Topics
- collatz-conjecture
- unsolved-problems
- number-theory
- sequences
Know your math trivia?
Play a free Math quiz and see how many you get right — no signup needed to start.
More Math facts
Math
What is the status of the Collatz Conjecture as of the early 21st century?
The Collatz Conjecture—propose any number, halve if even or triple-and-add-one if odd, repeat—remains unsolved despite its child-simple description.
Math
Which organization established the million-dollar reward that still awaits a proof of the Riemann Hypothesis?
A $1 million Clay Prize awaits anyone solving the Riemann Hypothesis, yet many top mathematicians avoid it, fearing decades of futility.
Math
What does Goldbach's Conjecture claim is true of every even number greater than 2?
Goldbach's Conjecture—every even number above 2 is a sum of two primes—passed computer checks through 4×10^18, but a proof eludes all methods.
Math
Which probability thought experiment involves a subject who wakes up unsure how many times she has already been woken, sparking a famous 1/3 vs 1/2 debate?
Sleeping Beauty wakes uncertain how many times she's woken, creating a paradox where rational people defend both 1/3 and 1/2 as the 'correct' probability.
Math
Roughly when did Babylonian scribes first begin marking an empty placeholder position within numbers, a precursor to zero?
The Babylonians used zero around 300 BCE but only in the middle of numbers, never at the end—creating ambiguity that plagued astronomy for centuries.
Math
In 2013, mathematician Harald Helfgott proved that every odd number greater than 5 can be written as the sum of how many prime numbers?
Every even number greater than 2 can be expressed as the sum of two primes, yet Goldbach's Conjecture remains unproven despite verification for trillions of cases.