Mathematical Competencies and Critical Thinking in Secondary Education: A PRISMA-Based Systematic Review (2019–2025)

<ns3:p>Background The integration of mathematical competencies and critical thinking in secondary education has become increasingly relevant to equip students with the ability to reason, argue, and solve complex real-world problems. Despite its recognized importance, this integration remains fragmented across curricula and inconsistently applied in classroom practice. Methods A systematic review was conducted in accordance with PRISMA 2020 guidelines to analyze empirical evidence published between 2019 and 2025. Searches were performed in Scopus, Web of Science, SciELO, and Dialnet databases. Inclusion criteria focused on open-access, peer-reviewed studies in English or Spanish addressing the integration of mathematical competencies and critical thinking in secondary education. From 1,457 records initially retrieved, 24 empirical studies were selected for full analysis. Results The studies reviewed indicate that mathematical competencies, defined as the ability to model, interpret, and solve problems through logical reasoning, are reinforced when integrated with critical thinking skills such as evaluation, argumentation, and evidence-based decision-making. Active methodologies, including Problem-Based Learning (PBL), Project-Based Learning (PjBL), STEM, and gamification, were identified as the most effective strategies to foster this integration. However, their implementation is often constrained by structural barriers such as limited teacher training, rigid curricula, and insufficient technological infrastructure. Conclusion Integrative, student-centered approaches supported by active learning methodologies enhance higher-order cognitive development and prepare learners to meet the demands of 21st-century education. Future research should address methodological standardization, teacher preparation, and institutional conditions to ensure the sustainable and equitable implementation of these strategies.</ns3:p>