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Number theory

math Maturity 11-13 Vital Level 3 Next article →

Number theory is a special branch of mathematics. It focuses on integers, which are whole numbers. These include positive numbers and their negative opposites.

Plimpton 322
Plimpton 322

Mathematicians look for patterns in these numbers. They study how numbers relate to each other. Some people study prime numbers, which only divide by themselves and one.

A 150x150 Ulam spiral of dots with varying widths (emphasis primes)
A 150x150 Ulam spiral of dots with varying widths (emphasis primes)

This study is very old. It is one of the oldest parts of math, just like geometry.

There are many ways to work with numbers. Some people use geometry to study them. Others use calculus and complex numbers. This is called analytic number theory.

Complex zeta
Complex zeta

Some people use algebraic structures like fields and rings. This is called algebraic number theory. There is also geometric number theory. Even more, people use probability or computers to study numbers. Each way helps solve different kinds of puzzles.

Continued fraction sqrt3
Continued fraction sqrt3

People have explored numbers for thousands of years. The Babylonians used clay tablets to list number sets.

Plimpton 322
Plimpton 322

A tablet called Plimpton 322 dates back to around 1800 BC. It shows they understood special number groups called Pythagorean triples. In Greece, the Pythagoreans studied numbers with a deep interest. Later, Euclid wrote about prime numbers and divisibility. Diophantus of Alexandria lived around the 3rd century AD. He wrote a famous collection of problems called the Arithmetica.

Georg Friedrich Bernhard Riemann
Georg Friedrich Bernhard Riemann

Math history also moved through Asia. A text called Sunzi Suanjing contains the Chinese remainder theorem. This was written between the third and fifth centuries. In India, the mathematician Āryabhaṭa lived from 476 to 550 AD. He had a method for solving equations called kuṭṭaka. Brahmagupta also studied equations in 628 AD. These thinkers helped build the foundation of number theory. Their ideas traveled through different cultures and languages.

Paul Erdos with Terence Tao
Paul Erdos with Terence Tao

Number theory is famous for very hard problems. Some rules are easy to understand but hard to prove. Pierre de Fermat wrote a famous rule in the 1600s. His Last Theorem took 358 years to prove!

Riemann Explicit Formula
Riemann Explicit Formula

Another puzzle is Goldbach's conjecture, which is still unsolved today. For a long time, people thought this math had no uses. That changed in the 1970s. Now, prime numbers help keep digital secrets safe. They are the basis for things like the RSA cryptosystem.

ECClines-3
ECClines-3
359 words

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🖼️ Images & Media (10)
File:A 150x150 Ulam spiral of dots with varying widths (emphasis primes).svg
A 150x150 Ulam spiral of dots with...
File:Plimpton 322.jpg
Plimpton 322.jpg
File:Georg_Friedrich_Bernhard_Riemann.jpeg
Georg_Friedrich_Bernhard_Riemann.jpeg
File:Paul Erdos with Terence Tao.jpg
Paul Erdos with Terence Tao.jpg
File:Continued fraction sqrt3.svg
Continued fraction sqrt3.svg
File:Complex zeta.jpg
Complex zeta.jpg
File:ModularGroup-FundamentalDomain.svg
ModularGroup-FundamentalDomain.svg
File:Riemann_Explicit_Formula.gif
Riemann_Explicit_Formula.gif
File:ECClines-3.svg
ECClines-3.svg
File:Computer History Museum (4145886786).jpg
Computer History Museum (4145886786).jpg
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