# What are prime numbers ?

### VERIFIED

### Ethan Lee

Recently completed an MSc in Mathematics, with teaching experience and training.

Think about a wall made of bricks. Each brick cannot be reduced in size and each brick is important to the wall. In maths, a prime number does the same job as one of those bricks. Except, instead of building a wall, a prime number builds a whole number such as 190 or 21. The exact definition of a prime number has already been given in a different answer to this question. However my answer should clarify that prime numbers exist for the same reason a brick exists; to build bigger numbers (through multiplication) in the same way that bricks are used to build a wall by cementing bricks together. One last point; neither 0 or 1 are prime. These are sometimes referred to as โthe zeroโ and โthe oneโ. However, I wonโt say the reason for this because that would over-complicate matters!

### VERIFIED

### James Ikin

I am passionate about helping people learn and overcome problems.

A "prime number" is a natural number greater than 1, that is only divisible by 1 and itself. So the key here is that prime numbers can't be formed by multiplying two smaller natural numbers.

### Ciara Daniels

3+ years teaching Maths

They are numbers that can only be divided by itself and 1 For example: 13

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