+118609 I just realised that you have put this question up twice and you now have two very different (both probably correct although I haven't checked) answers.
One below by problem - thank you problem and welcome to the forum. (I already left a private welcome message for you, you may need to press on your username to get into the message centre)
and one from admin instructing you how to use the calculator.
Both good answers.
Please don't post questions twice, it just fills up the forum with 'spam'.
