hat formula?

[SweetHina]

I'm making this beanie (without the brim) for this guy I like.
So I looked around to see how to make a basic one & I saw this formula:

http://www.mielkesfarm.com/bsic_hat.htm

I don't understand it, I mean right after B. Can someone give me examples of the equation?

this is the basic I'm gonna make, just a plain black color since that's what he wants:

http://www.jimmybeanswool.com/freeKn...attern_hat.asp

I'll be using size 8 needles, max size of 22" , the basic one shown above.

I tried doing the 70 sts that it says above, obviously it was too small.