This descriptive qualitative research aims to analyze and describe in depth the meaningful understanding of fifth grade students of Al Ihsan Yapis Elementary School Kotaraja about the material of changes in the state of matter and heat transfer through a simple practicum method. The research subjects consisted of 25 students and 1 class teacher. Data were collected through triangulation techniques which included participatory observation, documentation of the learning process, and in-depth interviews. The data analysis flow used the Miles and Huberman interactive model which consisted of data reduction, data presentation (data display), and drawing conclusions. The results of the study showed that the simple practicum method was effective in building students' meaningful understanding through five core learning activities (1) managing simple practicum tools and materials, (2) conduction practicum using a metal spoon, (3) radiation practicum through the sensation of warmth around a candle flame, (4) practicum on changes in the melting state of granulated sugar, and (5) practicum on the anomaly of a water-filled balloon above a candle to trigger cognitive conflict. Overall, this practicum activity succeeded in reducing text verbalism, minimizing scientific misunderstandings, and showing indicators of deep understanding orally and in writing. Meanwhile, technical obstacles in the form of a noisy classroom were successfully overcome with structured group management.