There are how many Philippine regions again?

My old "Araling Panlipunan" book would probably say 12 regions, plus the National Capital Region. Your book should be more recent, but it's good to check online anyway.

• The National Statistical Coordination Board website says we have 17 regions, as of September 2007. (That "as of" is important!)
• The DMOZ Open Directory says 17 as well, and includes short descriptions of each region.
• The Regions of the Philippines Wikipedia entry says 17 too, and includes a history of the regional divisions, as well as links to the entries of each province.

I noticed that these sites of the three, only Wikipedia classified Palawan as belonging to Region 6. (It was transferred from Region 4B.) Which reminds me why it's good to check more than one source.