First 5 Prime Numbers

The first 5 prime numbers are:

• 2
• 3
• 5
• 7
• 11

To find the first five prime numbers, we start at 2 (remember that 1 is not classed as a prime number).

The only factors of 2 are 1 and 2. So 2 is prime (in fact two is the only even prime number!)

Next we test 3. Three has just two factors: 1 and 3. So 3 is prime.

Next we test 4. Four has three factors: 1, 2 and 4. So 4 is not prime (a number that is not prime is called composite)

Next we test 5. Five has just two factors: 1 and 5. So 5 is prime.

Next we test 6. Six has four factors: 1, 2, 3 and 6. So 6 is composite.

Now onto 7. Seven has just two factors: 1 and 7. So 7 is prime.

Next onto 8. Eight has four factors: 1, 2, 4 and 8. So 8 is composite.

Now onto 9. Nine has three factors: 1, 3 and 9. So 9 is composite.

Next testing 10. Ten has four factors: 1, 2, 5 and 10. So 10 is composite.

Now testing 11. Eleven has just two factors: 1 and 11. So 11 is prime.

We now have our first 5 prime numbers: 2, 3, 5, 7 and 11!

This calculator uses the Sieve of Eratosthenes to calculate the prime numbers from and to any given numbers under a million.

Try it and see!

Input any value into our Find Prime Numbers Calculator and it will find all the primes up to and including your value.

You can then take this information and copy and paste it somewhere else if you wish!

Our Prime Number Charts page is similar to the prime number lists on this page but contains charts giving all the prime numbers up to a certain value.

We have charts showing all the prime numbers up to...

• 100
• 150
• 200
• 1000
• 5000
• 10,000

There is also a Prime Number Calculator which will calculate all the prime numbers within chosen values up to a million.

Our Prime Numbers List page is similar to the prime number charts on this page but contains charts giving the first ... set of prime numbers.

We have charts showing ...

• the first 100 primes
• the first 200 primes
• the first 500 primes
• the first 1000 primes

There is also a Prime Number Tester which will tell you whether or not a given number is prime and tell you all the factors of that number.

The Sieve of Erastosthenes is a method for finding what is a prime numbers between 2 and any given number.

Eratosthenes was a Greek mathematician (as well as being a poet, an astronomer and musician) who lived from about 276BC to 194BC.

If you want to find out more about his sieve for finding primes, and print out some Sieve of Eratosthenes worksheets, use the link below.

Take a look at our Prime Number page which clearly describes what a prime numbers is and what they are not.

There are also many different questions about prime numbers answered, as well as information about the density of primes.

The Math Salamanders hope you enjoy using these free printable Math worksheets and all our other Math games and resources.

We welcome any comments about our site or worksheets on the Facebook comments box at the bottom of every page.