 # What is 5/11 + 9/12? This is how you add

 5 11
+
 9 12

## Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

Now we multiply 5 by 12, and get 60, then we multiply 11 by 12 and get 132. Now for the second term. You multiply 9 by 11, and get 99, then multiply 11 by 12 and get 132. This gives us a new problem that looks like so:

 60 132
+
 99 132

## Step 2

Since our denominators match, we can add the numerators.

60 + 99 = 159

So what's the answer so far?

 159 132

## Step 3

Can this fraction be reduced?

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

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

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

 159 132
÷ 3 =
 53 44

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...

Nope. Try the next prime number, 19...

Nope. Try the next prime number, 23...

Nope. Try the next prime number, 29...

Nope. Try the next prime number, 31...

Nope. Try the next prime number, 37...

Nope. Try the next prime number, 41...

Nope. Try the next prime number, 43...

Nope. Try the next prime number, 47...

No good. 47 is larger than 44. So we're done reducing.

Congratulations! Here's your final answer to 5/11 + 9/12

 5 11
+
 9 12
=
 53 44
© 2014 Randy Tayler