Factorising examples

Example 1

Factor the number 12

Write down the number and put two ladders up against it.

Draw 2 ladders below a number side by side

Then write the numbers from 1 down the left ladder.

On the first ladder start with one and ascend the numbers on each rung until you get to half the number you are trying to factorise

Now fill the right ladder with the numbers that multiply to give 12.

On the second ladder start with the number you are factorising and descend in 2's until you get to 2 match opposing rungs up, this will give you the factors of the number

Therefore the factors of 12 are:

1 and 12

2 and 6

3 and 4

Alternatively the factors of 12 are 1, 2, 3, 4, 6 and 12

Example 2

Factor the number 15

Therefore

So start with the first ladder and descend to 5 only

And

15 is quite difficult because it only has 2 factors 15 and 5 so count down in 5's on the second ladder match the opposing rungs and 5 goes into 15 3 times

Therefore the factors of 15 are:

1 and 15

3 and 5

Alternatively the factors of 15 are 1, 3, 5 and 15.

Example 3

Factor the number 6

Therefore

factorise 6

And

factorise 6

Therefore the factors of 6 are:

1 and 6

2 and 3

Alternatively the factors of 6 are: 1, 2, 3 and 6.