During May 2025, Robert C. Green enhanced the mphowardlab/essential-math repository by developing comprehensive documentation for the substitution method in solving second-order ordinary differential equations. He authored a new Markdown section, written in LaTeX and Markdown, that guides users through the substitution technique with detailed, context-rich examples from kinematics and incompressible flow in a cylinder. His technical writing focused on improving user onboarding and discoverability, updating the table of contents for easier navigation. While the work was limited to a single feature, it demonstrated depth in both differential equations and technical communication, providing clear, practical guidance for users of the repository.