For every birdhouse, you need 1/2 of a box of nails to build it.
Using that logic we can assume that for every birdhouse you add 1/2 to get to your final answer.
1 birdhouse: 2 birdhouses: 3 birdhouses: 4 birdhouses: 5 birdhouses:
1/2 2/2 3/2 4/2 5/2
Now, we know that the answer is that we need to have 5/2 boxes of nails to build 5 birdhouses.
5/2 can also be converted into 2 1/2.
So 2 1/2 boxes of nails would be needed is the final answer
