I lost my iphone 5 and how can i find it?

I had that app called find my iphone and it says its offline. It might be dead to. Where I last put it at is around the field. I don't know if someone stole it or not. How can I find it at the school. Is there a way without a find my Iphone app. I checked everywhere in the field too. Do you guys think they stole it or turned it back to the lost and found. I don't want to tell my about it to she will get mad.

I lost mine at the gym and looked everywhere for it and I knew my mom would get mad, just face the music before Christmas pasts! You could get a better phone.