First, you need to ask for it as your Christmas/birthday gift or something like that. If they think it's too expensive for a gift, then pay for as much of it as possible as you can with YOUR OWN money. If they still think it's too expensive or are concerned on the pros and cons of it, then tell them that many adults their ages enjoy iPads too, and you should offer to let them use it when they are waiting in the car to pick you up from sports practice, after-school activities, etc. iPads are capable of downloading games, books, and movies, and can also surf the Internet. Your parents may be interested in some of these things. The only con of the iPad is its price, which may seem daunting at first, but in the end, I'm willing to bet your parents will be glad they bought it.
Parents are hard to convince.But i can tell you that iPad its not worth buying you better get an iPod its has more app than iPad its more personal for you if you still want an iPad then you go buy it.....
Explain to them that while you know the iPad is VERY EXPENSIVE, you'd really like one. Tell them that by the time you make the rent/house payment, utilities, buy the food, etc you just can't possibly swing getting it yourself.
I think that instead of asking for the iPad 3 you should ask for the iPad 2 because it is cheaper and basically the same thing. Hope this helped! P.S. Tell them you could use it for school and that everyone of your friends has one! P.P.S Make a Word document or a handwritten list (written very neatly in ink) of all the reasons they should get you an iPad. How do you think I got mine?