my kids enter wronge passwords several times until the ipad says"connect to iTune" but the ipad does not appear on the iTune.I know the correct password.

You've connected the iPad via cable to your computer, and your computer's iTunes is up-to-date ? If it's icon isn't showing then try one of these troubleshooting pages :

PC : iPhone, iPad, or iPod not recognized in iTunes for Windows - Apple Support

Mac : If you don't see your connected device in iTunes for Mac - Apple Support

If the iPad is disabled then you'll need to reset the iPad back to factory defaults, after which you can restore to your backup