The discussion centers on the application of the parallel axis theorem to calculate the area moment of inertia, with the original poster struggling to find an error in their solution. They discovered that the theorem can determine the moment of inertia about any axis using the moment about a parallel axis through the center of gravity. Key advice includes ensuring that only three moments of inertia need to be added, with the parallel axis theorem applied to specific areas while not needed for others. Additionally, verifying the accuracy of input numbers is crucial, and using a spreadsheet for calculations is recommended for better accuracy. The conversation emphasizes the importance of correctly applying the theorem and checking calculations to resolve the issue.