Investigating capacity and mass using a problem-solving task : a lesson study with primary school students

Abstract

This report presents a lesson study conducted with Year 4 and 5 students at Gozo College Ġużé Aquilina Primary and Special Unit Sannat, focusing on exploring the relationship between mass and capacity through problem-solving. The open-ended investigation is centred around a real-world scenario, which challenges students to investigate the common misconception that 1 litre always equals 1 kilogram. Through a hands-on approach involving different liquids and measuring tools, students collaborated in mixed-ability groups to compare, calculate and reason mathematically. The lesson integrated Universal Design for Learning (UDL), formative assessment and inclusive pedagogies to ensure all learners could participate meaningfully. Reflections from the teaching team highlighted key student misconceptions, strengths in collaboration and the value of structured inquiry for deepening conceptual understanding. The study illustrates how lesson study fosters professional collaboration, inclusive teaching strategies and responsive lesson design in support of the 21st century skills.