After charging iPad completely I can only use for a few hours of games or searching web and I have to charge it?

If your iPad is older then the battery may be just getting too old. When it becomes intolerable Apple will replace the battery for you for around $99 I think. Or it may be time to upgrade.

How many hours is - a few?

Games can be very taxing for the iPad and thus drain the battery quickly.

How many hours does the battery last? What games are you playing?

~Lyssa