A funny thing happened on the way to advanced project management. Too many want the mantle but too few want to do the math. In fact, the PMBOK 4th edition has less math in it than the 3rd edition.
Project managers are most often judged on their metric performance--cost and schedule, etc--but few want to invest in the math skills to drive the metrics better.
For those wanting to catch up a bit, I strongly recommend the 15 minute videos at the online Khan Academy. You can start back in the 5th grade and work yourself through a graduate education in math and statistics. And, it's free. And, it's in bite size chucks. Here's a sample:
