There is little testing on the formulas. You will need to be able to interpret the results, such as how to tell if your CPI is good or bad, and how it affects the overall project. Many of them have tricks you can use like "above 1 is good and below 1 is bad" and such.
Training for Project Management Professional (PMP)®, PMI Agile Certified Practitioner (PMI-ACP)®, and Certified Associate in Project Management (CAPM)®