Kengkaj Sathianpantarit wrote:

Unfortunately, Head First books I have read so far don't deal with any formula

So I cannot figure it out how Head First style handle many hard remember finance formulas.

That's an excellent point, and I'm really glad you brought it up. Jenny and I really had to put a lot of effort into the formulas to make them easy to understand and remember.

Here's the thing about the formulas that you need to know for the PMP exam. They are really hard to memorize if you don't understand why they're there. But if, rather than committing them to memory, you take the time to understand why you need them and how they're useful, they're much easier to remember.

And that's the approach that we ended up taking. We made a rule for ourselves: we never ask our readers to memorize anything. That means we need to give plenty of explanation, and a whole lot of practice. Luckily, the earned value management (EVM) formulas really do make sense, especially if you think about them from the sponsor or customer's perspective, since they give you a way of measuring how much actual value you've delivered to the customer.

Our section on the EVM formulas is much longer than the sections in other books, because we give a real-life scenario of a project running into cost overruns, and we show you how a project manager could use EVM to solve that problem. We had to take the time to explain each formula from more than one perspective (because that's an effective way of learning, and a basic Head First principle). And we gave many exercises and examples so the readers can learn from them.

We took a similar approach towards critical path analysis, finding the float (or slack) for any activity, and calculating ES, EF, LS and LF. We distributed a free "critical path drill" PDF that shows this -- it's the same as what's in the book -- because we think it's a good example of our approach towards other technical areas.

You can download our critical path drill here:

http://www.headfirstlabs.com/PMP/criticalpath/ -- I think that will help show you the kind of approach we took towards some of the more technical material.