<![CDATA[The sluggish learning interest and high levels of academic anxiety among students due to the rigid presentation of geometry material isolated from sociocultural realities are the background of this research. These obstacles trigger students' failure to visualize spatial figures independently in school mathematics learning. The main focus of this study is to explore the manifestation of ethnomathematics and the similarities of geometric shapes in traditional culinary products, namely the West Javanese kue blok (block cake) and the metal bars of the saron gamelan instrument. The steps of this descriptive qualitative research with an ethnographic approach are operated through purposive sampling involving traditional craftsmen and outlet owners. The actual data collection procedure is collected in depth through participatory observation techniques, semi-structured interviews, and structured documentation, which are then processed using an interactive analysis model including data reduction, presentation, and drawing conclusions. The research findings show that the making of kue blok reflects the three-dimensional dimensions of the block, the linear equation of the recipe, and the philosophical value of simplicity. Meanwhile, the anatomy of the saron contains the geometric concepts of the plane plane of the trapezoid, rectangle, and the transformation of mechanical energy into acoustic vibrations of the pitch precisely. The main conclusion confirms that contextualizing mathematics based on local Indonesian wisdom has proven effective in boosting intellectual agility while supporting the sustainable preservation of national cultural heritage. Educational practitioners are recommended to design daily lesson plans that consistently optimize real-world objects around the classroom. ABSTRAK Kelesuan minat belajar serta tingginya tingkat kecemasan akademik peserta didik akibat penyajian materi geometri yang kaku dan terisolasi dari realitas sosiokultural melatarbelakangi penelitian ini. Hambatan tersebut memicu kegagalan siswa dalam memvisualisasikan bangun ruang secara mandiri pada pembelajaran matematika sekolah. Fokus utama kajian ini adalah mengeksplorasi manifestasi etnomatematika dan kesamaan bentuk geometri pada produk kuliner tradisional kue balok khas Jawa Barat dan bilah logam instrumen gamelan saron. Langkah-langkah penelitian kualitatif deskriptif dengan pendekatan etnografi ini dioperasikan melalui penarikan sampel secara purposive yang melibatkan pengrajin adat dan pemilik outlet. Prosedur pengumpulan data aktual dihimpun secara mendalam lewat teknik observasi partisipatif, wawancara semi-terstruktur, serta dokumentasi terstruktur, yang selanjutnya diolah menggunakan model analisis interaktif meliputi reduksi data, penyajian, dan penarikan kesimpulan. Temuan penelitian menunjukkan bahwa pembuatan kue balok merefleksikan dimensi tiga dimensi balok, persamaan linier resep, dan nilai filosofis kesederhanaan. Sementara itu, anatomi saron mengandung konsep geometri bidang datar trapesium, persegi panjang, serta transformasi energi mekanik menjadi getaran akustik laras nada secara presisi. Simpulan utama menegaskan bahwa kontekstualisasi matematika berbasis kearifan lokal nusantara terbukti efektif mendongkrak ketangkasan intelektual sekaligus mendukung pelestarian warisan budaya nasional secara berkelanjutan. Praktisi pendidikan direkomendasikan merancang rencana pelaksanaan pembelajaran harian dengan mengoptimalkan benda nyata di sekitar ruang kelas secara konsisten. ]]>
