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# Goldbach's conjecture facts for kids

**Goldbach's conjecture** is one of the oldest unsolved problems in number theory and in all of mathematics. It states:

## Origins

On 7 June 1742, the Prussian mathematician Christian Goldbach wrote a letter to Leonhard Euler (letter XLIII) [1] in which he proposed the following conjecture:

- Every integer greater than 2 can be written as the sum of three primes.

He considered 1 to be a prime number, a convention subsequently abandoned. A modern version of Goldbach's original conjecture is:

- Every integer greater than 5 can be written as the sum of three primes.

Euler, becoming interested in the problem, answered by noting that this conjecture would follow from a stronger version,

- Every even integer greater than 2 can be written as the sum of two primes,

adding that he regarded this a fully certain theorem ("*ein ganz gewisses Theorema*"), in spite of his being unable to prove it.

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Goldbach's conjecture Facts for Kids.