All my worlds on Minecraft pocket edition on iPad are creative, is there anyway I can change them to survival?
There is one way... You just need access to the iPads file system. This can be done by jailbreaking and installing iFile, or you can install phone explorer for your computer. Then you go into /var/applications/minecraftPE/documents/Minecraft Worlds.
On your device, go into minecraft and make a new survival world. Call it something different to all your other worlds.
Refresh Phone explorer then go into the folder that has the name of the minecraft world you just created. Delete the "chunks.dat" and go back to your minecraft worlds.
Then go into the creative world folder which you want to change to survival, and copy the "chunks.dat". Go back into the survival world and paste the file.
On your device, close minecraft propperly, then open again. Go into the survival world you made and your creative world will be there. (somewhere)
Sorry it's all a bit complex but it's the only way I know.