Prime & Composite Numbers
Prime NumbersA Prime Number can be divided evenly only by 1 or itself. And it must be a whole number greater than 1.
For example: 5 is prime, as only 1 and 5 divide it, whereas 6 is composite, since it has the divisors 2 and 3 in addition to 1 and 6. Factors of 1 and the number itself makes the number prime. 2: 1 and 2 only even prime number 3: 1 and 3 5: 1 and 5 7: 1 and 7 |
Optimus ~ Prime Number |
Composite NumbersA Composite Number can be divided evenly
by numbers other than 1 or itself. For example: 4 is composite, since it has divisors of 2 and 2 in addition to 1 and 4. Having more than 2 factors (1 & itself) makes the number a composite number. 4: 1, 2, and 4 6: 1, 2, 3, and 6 8: 1, 2, 4, and 8 9: 1, 3, and 9 |
Eratosthenes - Greek Mathematician Born: 276 BC in Cyrene, North Africa (now Shahhat, Libya)
Died: 194 BC in Alexandria, Egypt
A prime number is a number that can be divided evenly only by 1 and itself. “Divided evenly” means that the result is a whole number, with no remainder. Prime numbers and their properties were first studied extensively by ancient Greek mathematicians, including Eratosthenes (pronounced AIR-a-TOSS-the-knees).
Sieve of Eratosthenes
In mathematics, the Sieve of Eratosthenes is a simple, ancient algorithm for finding all prime numbers up to a specified integer. It works efficiently for the smaller primes (below 10 million). It was created by Eratosthenes, an ancient Greek mathematician.