In the 17th century, mathematicians like Fermat, Euler and Gauss began to examine the patterns that exist within prime numbers. This sieve enables someone to come up with large quantities of prime numbers.īut during the Dark Ages, when intellect and science were suppressed, no further work was done with prime numbers. With these multiples crossed out, the only numbers that remain and are not crossed out are prime. So for this chart, you would cross out the multiples of 2, 3, 5 and 7. Since 6, 8, 9 and 10 are multiples of other numbers, you no longer need to worry about those multiples. For example, with a grid of 1 to 100, you would cross out the multiples of 2, 3, 4, 5, 6, 7, 8, 9, and 10, since 10 is the square root of 100.
Eratosthenes put numbers in a grid, and then crossed out all multiples of numbers until the square root of the largest number in the grid is crossed out. This algorithm is one of the earliest algorithms ever written. In 200 B.C., Eratosthenes created an algorithm that calculated prime numbers, known as the Sieve of Eratosthenes. This grid can be used as a Sieve of Eratosthenes if you were to cross out all of the numbers that are multiples of other numbers.
