How do you write 36 as a product of its prime factors?

What is a prime number?
This is a number which can only be divided by 1, and itself. 1 is not considered to be a prime number. The first few prime numbers are: 2, 3, 5, 7, 11, 13. Any even number can be divided by 2 so it is not a prime number.
Writing 36 as a product of its prime numbers:
Firstly, 36 is even so it can be divided by 2. We can write 36 as 2 x 18. 

Now let’s focus on 18. 18 can be divided by 2 again. So far, we have:
2 x 2 x 9.

Let’s divide up 9 into its prime factors. 9 is 3 x 3.

Now we focus on all of the prime numbers on the Prime Factor Tree.

So, we can write 36 as 2 x 2 x 3 x 3.