This monograph presents the English academic version of a Master’s Thesis documenting the design, implementation, and analysis of a structured educational intervention aimed at improving mathematics learning in students with Attention-Deficit/Hyperactivity Disorder (ADHD). The intervention was implemented in real classroom settings in Algebra I and Geometry I courses and was based on a structured instructional architecture integrating explicit instruction, task segmentation, visual and manipulative supports, guided practice, and continuous formative assessment. The project emphasizes the development of conceptual understanding, sustained attention, behavioral self-regulation, and academic autonomy in students with ADHD. The study combines classroom observation, analysis of student work, digital platform records, and portfolio-based assessment to evaluate the effectiveness of the intervention. The results illustrate how structured and multisensory instructional approaches can support mathematical reasoning and improve engagement and persistence in students with attention-related learning difficulties. The document includes detailed methodological explanations, pedagogical discussion, and extensive documentary evidence of classroom practice. The appendices provide instructional materials, descriptions of intervention scenarios, and anonymized visual evidence illustrating the implementation process. This work aims to contribute to the fields of mathematics education, inclusive education, and evidence-based instructional design by offering a replicable framework for supporting students with ADHD in secondary mathematics classrooms. This publication constitutes the English academic version of the original Spanish work, which has been deposited separately to preserve the integrity of both linguistic versions.