<![CDATA[Penelitian ini dilakukan di SMA Negeri 1 Calang selama tiga bulan sejak bulan Januari sampai Maret 2020 bertujuan untuk meningkatkan pemahaman melalui penggunaan pendekatan Contextual Teaching and Learning (CTL) pada materi reaksi reduksi oksidasi siswa kelas X IPA 2 SMA Negeri 1 Calang. Penelitian ini merupakan penelitian tindakan kelas (PTK) yang terdiri atas 2 siklus. Subyek penelitian adalah siswa-siswi Kelas X IPA 2 SMA Negeri 1 Calang tahun pelajaran 2019/ 2020 sebanyak 21 siswa. Analisis data menggunakan teknik analisis deskriptif komparatif dan analisis deskriptif kualitatif hasil observasi. Melalui penggunaan pendekatan Contextual Teaching and Learning (CTL) pada reaksi reduksi oksidasi mata pelajaran kimia siswa kelas X IPA 2 pada SMA Negeri 1 Calang diperoleh hasil tes pada siklus I dengan persentase ketuntasan 71,4 % nilai rata-rata kelas 72,8 dan meningkat pada hasil tes siklus II 85,7 % dengan nilai rata-rata kelas 78,2. Pada kedua siklus ini terjadi perubahan aktifitas dan perolehan nilai yang signifikan bila dibandingkan dengan pra siklus dengan ketuntasan belajar yang hanya mencapai 52,4 % dan nilai rata-rata adalah 69,1. Dengan demikian melalui penggunaan pendekatan Contextual Teaching and Learning (CTL) dapat meningkatkan pemahaman siswa pada materi reaksi reduksi oksidasi siswa kelas X IPA 2 SMA Negeri 1 Calang.Kata Kunci : Pendekatan Contextual Teaching and Learning (CTL), Reaksi Reduksi Oksidasi.This research was conducted at SMA Negeri 1 Calang for three months from January to March 2020 aimed at increasing understanding through the use of the Contextual Teaching and Learning (CTL) approach to the oxidation reduction reaction material for students of class X IPA 2 SMA Negeri 1 Calang. This research is a classroom action research (CAR) which consists of 2 cycles. The research subjects were students of Class X IPA 2 SMA Negeri 1 Calang in the 2019/2020 school year as many as 21 students. Data analysis used comparative descriptive analysis techniques and qualitative descriptive analysis of observations. Through the use of the Contextual Teaching and Learning (CTL) approach to the oxidation reduction reaction of the chemistry subjects of class X IPA 2 at SMA Negeri 1 Calang, the test results in the first cycle were obtained with the percentage of completeness 71.4%, the average grade of 72.8 and increasing on the second cycle test results 85.7% with an average grade of 78.2. In these two cycles there was a significant change in activity and score when compared to the pre-cycle with learning completeness which only reached 52.4% and the average score was 69.1. Thus, through the use of the Contextual Teaching and Learning (CTL) approach, students can improve students' understanding of the material for oxidation-reduction reactions of class X IPA 2 SMA Negeri 1 Calang.Keywords: Contextual Teaching and Learning (CTL) Approach, Oxidation Reduction Reaction. ]]>
