Worked on the TUDelft-MUDE/book repository to address a critical issue in the Exercise section, correcting the Divergence Theorem formula to ensure mathematical accuracy for learners. The update involved replacing an incorrect surface integral over volume with the appropriate volume integral, fully aligning the exercise with the Divergence Theorem. This targeted bug fix was implemented using Jupyter Notebook and leveraged expertise in physics and technical writing to provide clear documentation and maintain codebase stability. The change improved the accuracy of educational materials, reduced potential confusion for students, and was prepared for deployment in the next release with minimal disruption to existing content.