 # What is 1/3 + 4/5? 1 3
+
 4 5

## 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 1 by 5, and get 5, then we multiply 3 by 5 and get 15. Now for the second term. You multiply 4 by 3, and get 12, then multiply 3 by 5 and get 15. This gives us a new problem that looks like so:

 5 15
+
 12 15

## Step 2

Since our denominators match, we can add the numerators.

5 + 12 = 17

So what's the answer so far?

 17 15

## Step 3

Can this fraction be reduced?

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

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

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 15. So we're done reducing.