Prime and Composite Numbers

What are prime and composite numbers?

PRIME NUMBERS
A number having only two factors, number itself and one is called a prime number. In other words, a prime number can't be divided by any other number except by one and by itself. 

Some examples of prime numbers are; 2, 3, 5, 7, 11, 13 and so on. 

Keep in mind that all odd numbers are not prime numbers. For example, 9 is an odd number but not a prime number as it got a factor "3" other than itself and one as its factors. Similarly, number 15 in our previous example is not a prime number but an odd number.

COMPOSITE NUMBERS
Any number which has more than two factors is called a composite number. In other words numbers other than prime numbers and one are called the composite numbers. 

For example, 9 and 10 are the composite numbers.

Remember: 1 and 0 are neither prime nor composite numbers.

Knowledge of prime numbers and then prime factorization is the key to learn factoring polynomials.

Please print the following worksheet to practice the concept of prime and composite numbers: