## Monday, December 1, 2014

### Units and Prime Numbers

Factors and their multiples are very important throughout the maths of numbers.

When we write a number as two numbers multiplied together we say we have factorised the number.

We have seen that some numbers such as Twelve can be factorised into two numbers different to Twelve and that this is not possible for some numbers such as Seven.

One Seven is seven Ones and there is no way to factorise Seven without using seven. Such numbers are called Prime numbers.

One is One times One.

In the Game of Maths One is the basis of the counting.

When we are counting the thing we are counting is called the Unit.

We have been using an apple as a unit.

If they are packaged and we have three packs of apples then a unit is a pack of apples.

In the Game of Maths One is a unit and is used in building all other numbers through counting and addition.

One stands alone and is not a prime number, it is more important than that.

Prime numbers have prime importance.

Using multiplication and prime numbers all other numbers can be made. Other numbers are called composite numbers.

Any composite numbers can be split into prime factors.

Split any composite factors into pairs of factors until this is not possible.

For example

This can be split (factorised) as

Three is a prime number so cannot be split but Four can

Two is a prime number so we have finished

12 = 3 x 2 x 2 = 2 x 2 x 3 (usual to put the prime factors in numerical order)