Hidden storage use on iPad
I have a 16 GB iPad. It says that only 1.5 GB of storage is available on the device but when I click on 'manage storage' I can only see about 2.5GB in total from the listed apps which I can do anything about. I appreciate that the OS will take up some space but I can't understand why so much is being used. Is there any way to free up more storage?
iPad (4th gen) Wi-Fi, iOS 10.3.3