Ebay Gift Card

[jub04]

I received four $50.00 ebay gift card, how do I redeem them when I buy an item. 

For example, there's an item at $250.00. Can I use my cards and pay the rest with my Paypal account ?

How to enter the codes of each card in one transaction ? Is it possible, how to do it in the checkout process ???? I am lost !!!

Thanks for your help !!!