<![CDATA[Instruction for children aged 4–5 years requires activities that provide opportunities to explore, interact, and develop ideas independently. This study aimed to describe the use of loose parts in instruction and analyze the stimulation of six aspects of child development at KB Sinar Putra. The study employed a classroom action research (CAR) design across two cycles, each comprising planning, action implementation, observation, and reflection. The participants comprised 15 children in Group A aged 4–5 years, namely seven boys and eight girls. Data were collected through observations, interviews, and documentation, then analyzed descriptively using qualitative and quantitative methods by calculating the percentage of attainment in the Developing as Expected (BSH) category or higher. The findings showed that attainment of BSH or higher increased from 40% at baseline to 60% in Cycle I and 86.67% in Cycle II. Attainment across the six developmental aspects in Cycle II comprised religious and moral values at 80%, language at 80%, physical and motor development at 87%, social-emotional development at 87%, cognitive development at 86%, and arts at 87%. Thus, the 80% success criterion was met in Cycle II. These findings indicate that loose parts can serve as a flexible instructional alternative to support the integrated stimulation of children’s development. The practical implication is the need for material management, simple instructions, and teacher guidance to keep activities safe and directed while maintaining opportunities for children to explore.]]>
