Abstract:

Educational goals globally emphasize the cultivation of citizens capable of utilizing acquired knowledge to solve real-world societal issues, as embodied by the Sustainable Development Goals (SDGs). However, a persistent challenge remains in translating students' high intrinsic motivation for social contribution into concrete, practical action plans. Furthermore, in a national survey of 6th-grade students in Japan conducted in 2025, while 80% of students believed that what they learn in science will be useful in the future, the percentage dropped to 63% when asked if they actively use it in their daily lives.

This study investigated the effectiveness of an interdisciplinary inquiry unit, "Can Algae Save the Sea? (Tackling Ocean Acidification)," implemented with 6th-grade elementary students in Japan (N=33). The unit systematically integrated Science (photosynthesis, pH), Mathematics (data analysis, graph presentation), and Social Studies (SDGs attainment index), treating knowledge as a tool rather than an endpoint for social problem-solving. The instructional design was anchored in the PPDAC cycle (Problem, Plan, Data, Analysis, Conclusion) to ensure a seamless transition from scientific understanding to societal proposal.

Building on this, we implemented a year-long Phased Inquiry-Based Learning (PIBL) model that wove mathematics, science, and social studies across three sequential phases:
- Foundation phase: Students built core scientific concepts and data literacy through hands-on experiments and data visualization tools.
- Inquiry phase: Learners performed statistical analyses on the global SDGs attainment index, critically evaluating data limitations and gaps to strengthen their critical thinking.
- Action phase: Drawing on data-driven insights, students formulated and presented actionable environmental solutions at both local and global scales.
- Pre- and post-unit questionnaires quantified shifts in practical action competence: 86% of students initially expressed the desire to act, but only 36% had concrete plans. - Post-unit, 83% demonstrated realistic proposals, marking a 47-percentage-point increase in students with concrete action plans. Qualitative analyses—such as 3D-printed cultivation platforms and biodegradable barrier designs—highlighted the fusion of scientific principles with engineering and environmental ethics.

Traditional project-based inquiry learning often suffers from heterogeneous skill requirements, gaps in data analysis, and concentrated teacher workload. By contrast, the PIBL model employed explicit scaffolding to guarantee data literacy and scientific reasoning while enabling students to acquire complex skills in a stepwise fashion. Teachers integrated AI-supported tools and micro-projects at strategic points and cultivated a culture of self-assessment and peer review through regular reflective sessions. Moreover, PIBL's flexible structure lent itself to diverse educational environments and international collaboration, positioning it as a structural reform capable of meeting future educational needs.

These findings suggest that intertwining multiple disciplines within a phased, real-world problem-solving framework effectively bridges the intent-action gap. The evidence-based model we propose is highly reproducible across other subjects and cultural contexts and holds promise for nurturing future global citizens who leverage scientific knowledge as a catalyst for sustainable societal change.

Keywords:

Interdisciplinary Learning, STEAM Education, SDGs, PPDAC Cycle, Elementary Education.