 # What is 9/12 + 2/8? This is how we add

 9 12
+
 2 8

## 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 9 by 8, and get 72, then we multiply 12 by 8 and get 96. Now for the second term. You multiply 2 by 12, and get 24, then multiply 12 by 8 and get 96. We now have a new problem, that looks like this:

 72 96
+
 24 96

## Step 2

Since our denominators match, we can add the numerators.

72 + 24 = 96

That gives us the sum, which is

 96 96

## 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:

 96 96
÷ 2 =
 48 48

Now, try the same number again.

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

 48 48
÷ 2 =
 24 24

Now, try the same number again.

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

 24 24
÷ 2 =
 12 12

Now, try the same number again.

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

 12 12
÷ 2 =
 6 6

Now, try the same number again.

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

 6 6
÷ 2 =
 3 3

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:

 3 3
÷ 3 =
 1 1

Now, try the same number again.

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

Congratulations! Here's your final answer to 9/12 + 2/8

 9 12
+
 2 8
=
 1 1
= 1
© 2014 Randy Tayler