3 birds were sitting on the fence. 6 more storks and 2 more birds came to join them. How many more storks than birds are sitting on the fence?

There are a total of 12 animals on the fence. If we take away the number of birds, we are left with the number of storks. 

There are 6 birds on the fence. 

This means that there are 6 storks on the fence.