<![CDATA[Penelitian ini dilatarbelakangi oleh rendahnya kemampuan berpikir kritis matematis siswa Indonesia, khususnya dalam menyelesaikan masalah non-rutin. Penelitian ini bertujuan untuk mengembangkan dan menguji efektivitas model Problem Based Learning–Flipped Classroom (PBL-FC) yang terintegrasi dengan kearifan lokal Baduy dalam meningkatkan kemampuan berpikir kritis matematis siswa. Desain penelitian menggunakan pendekatan Research & Development (R&D) dengan kerangka ASSURE untuk pengembangan model, serta desain quasi-eksperimen dengan kelompok kontrol pretest–posttest untuk menguji efektivitasnya. Penelitian melibatkan 60 siswa kelas lima SD Negeri Alaswangi 1, Lebak-Banten, yang dipilih berdasarkan kesiapan, motivasi, dan akses terhadap sumber belajar. Instrumen penelitian meliputi tes berpikir kritis matematis, lembar observasi pelaksanaan pembelajaran, serta kuesioner respons guru dan siswa. Data dianalisis menggunakan uji validitas dan reliabilitas, ANOVA, uji lanjut (post hoc), dan N-Gain. Hasil penelitian menunjukkan validasi ahli terhadap model sebesar 87,5% (sangat valid), keterlaksanaan pembelajaran 97,08% (sangat praktis), serta respons guru dan siswa masing-masing 91,67% dan 86,16% (baik hingga sangat baik). Peningkatan rata-rata kemampuan berpikir kritis matematis siswa lebih tinggi pada kelompok PBL-FC (73,91%) dibandingkan dengan kelompok PBL konvensional (56,83%). Hasil ANOVA menunjukkan efek signifikan dari kemampuan akademik (F=17,536; p<0,001), model pembelajaran (F=5,100; p<0,001), dan interaksi keduanya (F=2,100; p<0,001). Uji lanjut menegaskan adanya perbedaan signifikan antar kelompok kemampuan tinggi–sedang (9,76), tinggi–rendah (19,83), dan sedang–rendah (10,06) dengan p≤0,002. Kesimpulannya, model PBL-FC berbasis kearifan lokal Baduy efektif, valid, dan praktis untuk diterapkan dalam Kurikulum Merdeka, khususnya dalam meningkatkan kemampuan berpikir kritis matematis siswa. This research is motivated by the low mathematical critical thinking skills of Indonesian students, especially in solving non-routine problems. This study aims to develop and test the effectiveness of the Problem Based Learning–Flipped Classroom (PBL-FC) model integrated with Baduy local wisdom in improving students' mathematical critical thinking skills. The research design uses a Research & Development (R&D) approach with the ASSURE framework for model development, as well as a quasi-experimental design with a pretest–posttest control group to test its effectiveness. The study involved 60 fifth-grade students of Alaswangi 1 Elementary School, Lebak-Banten, who were selected based on their readiness, motivation, and access to learning resources. The research instruments included a mathematical critical thinking test, observation sheets for learning implementation, and teacher and student response questionnaires. Data were analyzed using validity and reliability tests, ANOVA, post hoc tests, and N-Gain. The results showed expert validation of the model at 87.5% (very valid), learning implementation at 97.08% (very practical), and teacher and student responses at 91.67% and 86.16% (good to very good), respectively. The average increase in students' mathematical critical thinking skills was higher in the PBL-FC group (73.91%) compared to the conventional PBL group (56.83%). ANOVA results showed significant effects of academic ability (F=17.536; p<0.001), learning model (F=5.100; p<0.001), and the interaction between the two (F=2.100; p<0.001). Further tests confirmed significant differences between the high-medium ability groups (9.76), high-low (19.83), and medium-low (10.06) with p≤0.002. In conclusion, the PBL-FC model based on Baduy local wisdom is effective, valid, and practical to be implemented in the Independent Curriculum, especially in improving students' mathematical critical thinking skills.]]>
