# Prime numbers

A prime number (or a prime) is a natural number greater than 1 that cannot be formed by multiplying two or more smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number.[1]

To test for whether a number n is prime, test whether the number is divisible by all integers from 2 to the square root of n.

This method trial division is very slow and can improved by other methods such as the AKS primality test.

## Activities

1. Review MathsIsFun: Prime and Composite Numbers. Create a list of prime numbers less than 100.
2. Review MathsIsFun: Prime Numbers Chart and Calculator. Compare your list of prime numbers less than 100 for accuracy. Use the prime number calculator to find a prime number greater than 1000.
3. Review Wikipedia: Generating primes and ExtendOffice: How to Generate Prime Numbers in Excel. Use Excel to create your own prime number generator.
4. Review Wikipedia: Generating primes and Prime number generators. Write your own program to generate prime numbers.