The theory of poker

I am currently reading the theory of poker....I am a decent card player and i did very well reading harington on hol vol 1&2 ....this book seems very advanced and i am having trouble with all the effective odds and implied odds. Basically its the math and technical stuff that is giving me a little trouble....has anyone experienced this book to be a little advanced...if so are there any readings that are a little easier to understand as far as the math goes