By inventing his “sieve” to eliminate nonprimes-using a number grid and crossing off multiples of 2, 3, 5, and above-Eratosthenes made prime numbers considerably more accessible.Įach prime number has exactly 2 factors: 1 and the number itself.
Such numbers, divisible only by 1 and themselves, had intrigued mathematicians for centuries. 194 BCE) devised a method for finding prime numbers. In addition to calculating the earth’s circumference and the distances from the earth to the moon and sun, the Greek polymath Eratosthenes (c. Let’s try an ancient way to find the prime numbers between 1 and 100.
A positive integer is a prime number if it is bigger than 1, and its only divisors are itself and 1. Each positive integer has at least two divisors, one and itself.
