Question concernin CC interest

[poundwise]

Ok, this is, I believe, on-the-one-hand, a pretty simple question. Then again, not necessarily. I'm perhaps being a little lazy by asking it instead of just looking into myself but I'll do both and will appreciate any helpful advice/answers.

I will use all hypothecial and low figures.

If you have a credit card with a 10.0% APR that has a balance on the last statement date of $1200, and you charge an item that costs $50 onto that card but make a $50 payment (in addition to the payment due monthly) to the card before the next statement date (or within 30 days, grace period) do you pay any interest on that $50 at all?

To explain my question: I know that if you have a card with $0 balance and you charge $50 on it but pay the balance in full prior to the next statement then you are not charged interest. But, if you already carry a balance and do not pay the balance in full, does it matter that the (in the example above) $50 was 'paid' for within the grace period for new purchases?

Hm.. I'll leave it at that for now. Any good info is appreciated.

[sweeps]

It depends. LINK (See section titled "Examples of balance computation methods...")

[boefixepa]

Yep, depends on the card, the terms, and all that jazz.