The easiest way to take the "math" out of it is to download the BleachCalc and let it do the calculations for you.

http://www.hal-pc.org/~mwsmith2/BleachCalc262.exe

It was written by one of our forum members. It's a real time-saver. And yes, until your pool clears up, you will want to maintain "shock" level for your chlorine.