I think the best book for learning "poker math" is Harrington on Holdem.

There are enough real life problems in there where he goes through the math step by step, that you learn enough to be able to put it into practice during your play.

I didn't absorb it all in the first reading, but I kept it as a bathroom reader for a year or two, and now most of it is embedded in my brain. I am surprised at how quickly I can analyze situations at the tables now.