 # What is 8/9 + 5/12? 8 9
+
 5 12

## Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 8 by 12, and get 96, then we multiply 9 by 12 and get 108. Do the same for the second term. We multiply 5 by 9, and get 45, then multiply 9 by 12 and get 108. The problem now has new fractions to add:

 96 108
+
 45 108

## Step 2

Since our denominators match, we can add the numerators.

96 + 45 = 141

 141 108

## Step 3

The last step is to reduce the fraction if we can.

To find out, we try dividing 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:

 141 108
÷ 3 =
 47 36

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...

No good. 37 is larger than 36. So we're done reducing.