In May 2025, Parker Green expanded the mphowardlab/essential-math repository by developing a new Undetermined Coefficients Skill Builder focused on second-order ordinary differential equations. Parker authored two original problems, each accompanied by detailed, step-by-step solutions designed to reinforce learners’ understanding of ODE techniques and structured problem-solving. The work emphasized technical writing and mathematics, using Markdown to deliver clear instructional content. No bug fixes were addressed during this period, as Parker concentrated on content development and collaborative recognition, including updating credits to acknowledge contributors. The depth of the solutions provided a comprehensive resource for students seeking to master advanced mathematical methods.