Hi! I think you answered my question about the calculator on the other thread. I have purchased the three Pearson practice tests and did two of them. There is no access to the periodic table/calculator, but they make a note that there will be an access to both on the real exam. It is fairly easy to navigate between problems using next/last buttons or something similiar to them. But in order to move from nonconsecutive problems such as 1 to 4, you have to pass other problems between them. If you want to go straight to a certain problem, you can go to "Review" page. Review page gives you a list of all the problems and shows you which ones you have answered/not answered. But I have been avoiding going through this page because it also shows you which questions are right/wrong even before you score your section. I'm not sure how the real PCAT will be. Finally, it seems to reflect the new changes very closely in terms of structure because the science sections contain several passages and the math sections many word-based problems as well. Hope this helps!