The list of prime numbers starts as follows:

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37........

All other whole numbers are known as composite and can be written as the product of prime factors.

This is known as prime factorisation. 

We use indices to tidy up long strings of the same number.

Examples

54 = 2 x 3 x 3 x 3 = 2 x 3³

Test it out if you're not sure how we got that!  3 x 3 x 3 = 27 x 2 = 54  - does that make sense now?

We've got one 2 and three lots of 3. We write that as 2 x 3³

Let's look at another couple of examples!

28 = 2 x 2 x 7 = 2² x 7

24 = 2 x 2 x 2 x 3 = 2³ x 3

How do you feel about this now? Ready to make a start?