Occasionally, the iPad may completely freeze where the buttons and screen become unresponsive and the user is unable to turn off the iPad. Here are some solutions to fix a frozen iPad.
Reset the iPad
Hold the Home & Wake/Sleep button simultaneous until the device restarts itself (about 5-10 seconds)
Wait it Out
You can wait until the device runs out of battery. From my experience, it will always turn back on when you charge it back up.
Restore the iPad
1. Connect the device to the computer
2. Launch iTunes and click the “iPad” button
3. Click on the ‘Restore iPad’ button
4. Confirm the restore