 # What is 6/9 + 4/12? 6 9
+
 4 12

## Step 1

Can you add yet? Nope! The denominators don't match. We need a common denominator. So next we take both denominators and multiply them. Next, take each numerator and multiply it by the denominator of the other term.

So, we multiply 6 by 12, and get 72, then we multiply 9 by 12 and get 108. Now for the second term. You multiply 4 by 9, and get 36, then multiply 9 by 12 and get 108. We now have a new problem, that looks like this:

 72 108
+
 36 108

## Step 2

Since our denominators match, we can add the numerators.

72 + 36 = 108

That gives us the sum, which is

 108 108

## Step 3

Now, do we need to simplify this fraction?

First, we attempt to divide it by 2...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

 108 108
÷ 2 =
 54 54

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

 54 54
÷ 2 =
 27 27

Now, try the same number again.

Nope. Try the next prime number, 3...

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

 27 27
÷ 3 =
 9 9

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

 9 9
÷ 3 =
 3 3

Now, try the same number again.

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

 3 3
÷ 3 =
 1 1

Now, try the same number again.

No good. 3 is larger than 1. So we're done reducing.