How to find my battery percentage number?

So I just recently purchased an iPhone 5. And I love it the battery lasts a lone time it yesterday I downloaded the updated iOS6.0.1.2 I thnk (latest version) it had my battery goin real quik. So I looked online for ways to downgrade back down or just anything. So I seen someone said resetting it should do it. So I did it.Bt now I have a battery with no percentage.

Smash it to pieces with a hammer. Then find the battery and put it in the microwave. Heat it up, and however many seconds it takes to explode is how much percent was in it. But then you have to get a new phone…