<![CDATA[This research is motivated by the fact that the teaching materials used for local culture lessons are still too general and lack a contextual connection to the students’ lives. This situation highlights the need for supplementary teaching materials that are more closely aligned with the students’ environment. The purpose of this study is to develop supplementary teaching materials based on local culture for fourth-grade IPAS lessons at Sekura Public Elementary School 02 and to determine the validity of the developed materials. The research method used was Research and Development (R&D) employing the ADDIE development model, limited to three stages: analysis, design, and development. Data were collected through interviews and questionnaires, then analyzed using qualitative and quantitative methods with a four-point Likert scale. The development stage included product creation, validation by subject matter experts, language experts, and design experts, as well as revisions based on the validators’ suggestions. The results showed that the supplementary teaching materials were categorized as highly valid, with validity scores of 98.61% from subject matter experts, 97.22% from language experts, and 97.22% from design experts. Thus, the development of a local culture-based teaching supplement in Sambas Regency for the IPAS subject in the fourth grade at Sekura Public Elementary School 02 is deemed highly valid and can be used to support more contextual and meaningful learning for students.]]>
