Free Worksheets, Lessons, Quizzes

Prime Factorisation


What is Prime Factorisation?

It is the multiplication of a number as the product of prime factors.

 

 

Explanation:

 

Find the prime factorisation of 12.


 

 

Step 1:

List all the factors of 12.

 

Number

Factors

12

1 , 2 , 3 , 4 , 6 , 12

 

 

Step 2:

Which factors of 12 are prime numbers?

 

1 , 2 , 3 , 4 , 6 , 12

 

 

Step 3:

Use only prime factors of 12 and do the downward division or upside-down division to divide 12 as follows;

 

downward-division-1

 

Step 4:

Now write the multiplication with the product of 12.

 

12 = 2 x 2 x 3

 

 

The answer can also be written with an exponent which is the shorthand for repeated multiplication.

 

 

* 2 is repeated twice in the above multiplication. So we also can write the answer as follows;

 

Prime factorisation of 12 is;

 

 

12 = 22 x 3