<![CDATA[AbstrakTujuan penelitian ini adalah untuk mengetahui apakah implementasi model pembelajaran CIRC berbasis Joyfull Learning efektif terhadap kemampuan penalaran matematis siswa pada materi Teorema Pythagoras. Pengumpulan data dilakukan dengan metode dokumen-tasi, tes, dan observasi. Berdasarkan hasil penelitian menunjukkan bahwa siswa pada kelas eksperimen telah mencapai ketuntasan klasikal. Hasil uji perbedaan dua rata-rata menun-jukkan bahwa rata-rata hasil tes kemampuan penalaran matematis siswa kelas eksperimen lebih dari rata-rata hasil tes kemampuan penalaran matematis siswa kelas kontrol. Berdasar-kan hasil tersebut dapat diketahui bahwa rata-rata kemampuan penalaran matematis siswa kelas eksperimen lebih baik daripada rata-rata kemampuan penalaran matematis siswa kelas kontrol. Hasil observasi menunjukkan bahwa persentase keaktifan siswa dalam pelaksanaan pembelajaran CIRC berbasis Joyfull Learning lebih tinggi daripada persentase keaktifan siswa pada pembelajaran ekspositori, dan aktivitas guru dalam mengelola pembelajaran CIRC berbasis Joyfull Learning mencapai kriteria sangat baik. Kata kunci:      CIRC; Joyfull Learning; Kemampuan Penalaran Matematis.  AbstractThe purpose of this study was to determine whether the implementation of the CIRC based Joyful Learning models effective against studentâs mathematical reasoning skills on the material Pythagorean Theorem. The population in this study is the eighth grade students of Junior High School of 1 Tlogowungu. Based on the results of the study showed that students in the experimental class have reached the classical completeness. The test results mean the difference of two shows that the average test results of mathematical reasoning skills experimental class students more than the average test results of studentâs mathematical reasoning skills control class. Based on these results it can be seen that the average of studentâs mathematical reasoning skills experimental class was better than average grade studentâs mathematical reasoning skills of control. Based on observations indicate that the percentage of active students in the implementation of CIRC based Joyful Learning models is higher than the percentage of active students in expository teaching and learning activities of teachers in managing the CIRC based Joyful Learning models achieving the criteria very well.  Keywords:         CIRC; Joyful Learning; Mathematical Reasoning Skills.]]>
