The best possible way to clear all of your information is to do a factory reset.
To do this:
1. Go to Settings menu.
2. Click on Backup & reset.
3. Click on Factory Data Reset.
4. You will be given the option to clear the contents of your SD card. If you would like to do this, check off the box.
5. Click Reset Tablet.
6. You will be given a message to ensure that you want to clear all of your content.
7. Click Erase Everything.
For more information regarding common troubleshooting issues, please visit Polaroid A10 Troubleshooting!