Integrating sustainability into primary mathematics education remains a significant challenge in Indonesia, particularly in aligning numeracy learning with Education for Sustainable Development (ESD) and green economy principles. This study aimed to design and validate the Green Economy and Numeracy Integration for Understanding Sustainability (GENIUS) learning model, a structured framework intended to integrate sustainability and green economy principles into primary mathematics education through contextualized, reflective, and student-centered instructional practices. Guided by constructivist learning theory, contextual learning, and the ESD competency framework, a mixed-methods design recruited 78 unique primary school teachers in Bogor City, West Java, selected through purposive sampling. Data were collected through questionnaires (n = 52), semi-structured interviews (n = 15), and classroom observations (n = 8), with overlapping participation across instruments, to examine teachers’ needs and instructional constraints. The needs analysis revealed that although most teachers showed positive attitudes toward sustainability-oriented instruction, major barriers included limited ESD understanding, rigid curriculum structures, and insufficient contextual resources. Based on these findings, the GENIUS model was developed with components including learning objectives, instructional syntax, roles of teachers and students, support systems, and contextual materials. Expert validation by mathematics education experts, ESD specialists, and experienced primary teachers used Aiken’s V to assess content and construct validity. Results indicate high validity across components (V ≥ 0.85), exceeding accepted thresholds and indicating coherence and practical feasibility. This study demonstrates the novelty of the GENIUS model for ESD numeracy learning.
Purnamasari et al. (Thu,) studied this question.