To calculate mass from weight on different planets, one must understand that weight is the product of mass and gravitational acceleration. In the example given, with a weight of 91 kg and gravitational acceleration of 9.782 m/s², the individual’s mass remains constant at 91 kg regardless of the planet. The confusion arose from misinterpreting the relationship between weight and mass. After rereading the problem, the original poster clarified their understanding. The discussion highlights the importance of grasping fundamental physics concepts for accurate calculations.