Find my iPhone says 'offline', how can I find it?

My iPad was stolen on Friday and when I try to find it using "find my iPhone" it says that it is "offline", when you would think that if a thief wanted to reset and then use it it would be connected to the internet at some point, but no the map (I'm using a PC to find it) doesn't even say that it has come up once, and it's been 5 days. Tomorrow I'm going to give the serial number to the police in case it is handed in, although that is unlikely as it was stolen from my school (we use iPads in class).

I've spoken to every person in my school who could have had my iPad handed in to them and they say that they haven't heard anything.

So with the find my iPhone thing, is that going to tell me when it was last seen or do I have to be actually looking at the map at the time it is being tracked? I've set it so I'll get an e-mail if it's found, so will this happen as soon as it connects to the internet?

I'm not used to apple stuff, and this seems so straightforward but confusing at the same time.

The theif as resetted or swichted it off as soon as he oned it you can track it back

If offline you can't, but it will prevent them from turning it back on and using it or selling it. Make sure you activate lost mode on find my iphone, and put a message on the screen.