How to work out if a given number is a prime number or not, based on the properties of prime numbers.
The fundamental theorem of arithmetic states that a composite number can be expressed as the product of prime numbers. Prime numbers are often seen as ‘building blocks’ by mathematicians in number theory. 13 ÷ 6 = 2 remainder 1.ġ5 is not an example of a prime number because it can be divided by 5 and 3 as well as by itself and 1.ġ5 is an example of a composite number because it has more than two factors. Dividing a prime number by another natural number results in numbers leftover e.g. What is a prime number?Ī prime number is a whole number greater than 1 with only two factors – themselves and 1.Ī prime number cannot be divided by any other positive integers without leaving a remainder, decimal or fraction.Īn example of a prime number is 13.
Here we explain what exactly this means, give you a list of the prime numbers children need to know at primary school and provide you with some practice prime number questions and examples. A prime number is a number that can only be divided by itself and 1 without remainders.
