 # What is 2/12 + 5/9? 2 12
+
 5 9

## Step 1

We can't add two fractions with different denominators (the bottom number). So you need to get a common denominator - both bottom numbers need to match. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

So we multiply 2 by 9, and get 18, then we multiply 12 by 9 and get 108. Do the same for the second term. We multiply 5 by 12, and get 60, then multiply 12 by 9 and get 108. So now our fractions look like this:

 18 108
+
 60 108

## Step 2

Since our denominators match, we can add the numerators.

18 + 60 = 78

 78 108

## Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

To find out, we try dividing it by 2...

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

 78 108
÷ 2 =
 39 54

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:

 39 54
÷ 3 =
 13 18

Now, try the same number again.

Nope. Try the next prime number, 5...

Nope. Try the next prime number, 7...

Nope. Try the next prime number, 11...

Nope. Try the next prime number, 13...

Nope. Try the next prime number, 17...

No good. 17 is larger than 13. So we're done reducing.