Kemampuan pemecahan masalah matematis sangat penting bagi siswa. Namun, pada kenyataannya masih banyak siswa mengalami kesulitan, terutama dalam menyelesaikan soal cerita seperti soal lingkaran. Kurangnya bahan ajar menjadi penghambat dalam pembelajaran siswa, sehingga diperlukan bahan ajar untuk meningkatkan kemampuan pemecahan masalah matematis. Penelitian ini bertujuan untuk mengembangkan E-LKPD berbasis flipbook dalam pembelajaran berdiferensiasi untuk meningkatkan kemampuan pemecahan masalah matematis siswa pada materi lingkaran. Bahan ajar dikembangkan untuk mendukung pembelajaran berdiferensiasi dengan siswa dikelompokkan berdasarkan kemampuan belajar awal yaitu tinggi, sedang, atau rendah dan gaya belajar yaitu auditori, kinestetik, dan visual. Jenis penelitian yang digunakan adalah Research and Develop (R&D) dengan menggunakan model pengembangan ADDIE yaitu Analyze, Design, Develop, Implement, and Evaluate. Subjek yang digunakan yaitu 35 siswa kelas XI-3 di SMA Negeri 2 Kuningan. Teknik pengumpulan data menggunakan angket, wawancara, dan tes. Instrumen yang digunakan yaitu lembar angket validasi dan kepraktisan, pedoman wawancara serta tes kemampuan pemecahan masalah matematis. Sumber data diperoleh dari dosen, guru, dan siswa. Data diperoleh dari hasil validasi ahli materi, ahli media, kepraktisan guru, kepraktisan siswa, dan soal pre-test serta soal post-test. Teknik analisis data yang digunakan meliputi uji kevalidan, uji kepraktisan, dan uji N-Gain. Kevalidan E-LKPD diuji oleh tiga validator ahli materi dan dua ahli media. Hasil validasi dari ketiga ahli materi memperoleh persentase sebesar 90%, menunjukkan E-LKPD sangat valid. Hasil validasi dari kedua ahli media memperoleh persentase sebesar 86%, menunjukkan E-LKPD sangat valid. Kepraktisan E-LKPD diuji oleh guru dan siswa. Hasil uji kepraktisan menggunakan angket dari guru memperoleh persentase sebesar 93% menunjukkan E-LKPD sangat praktis, sedangkan persentase dari siswa sebesar 88% dengan kategori sangat praktis. Hal ini menunjukkan bahwa E-LKPD yang telah dikembangkan sangat praktis. Hasil uji N-Gain memperoleh nilai rata-rata sebesar 0,78 yang dikategorikan tinggi. E-LKPD berbasis flipbook dalam pembelajaran berdiferensiasi pada materi lingkaran dikatakan valid, praktis dan dapat meningkatkan kemampuan pemecahan masalah matematis siswa. Saran untuk peneliti selanjutnya pengembangan E-LKPD dapat menggunakan platform atau aplikasi lain seperti wizer.me yang dapat memfasilitasi siswa dalam menjawab E-LKPD.
Kata Kunci: E-LKPD, Flipbook, Kemampuan Pemecahan Masalah Matematis, Lingkaran, Pembelajaran Berdiferensiasi.

Mathematical problem solving skills are very important for students. However, in reality, many students still experience difficulties, especially in solving story problems such as circle problems. The lack of teaching materials is an obstacle in student learning, so teaching materials are needed to improve mathematical problem solving skills. This study aims to develop flipbook-based E-LKPD in differentiated learning to improve students' mathematical problem solving skills on circle material. Teaching materials are developed to support differentiated learning with students grouped based on initial learning abilities, namely high, medium, or low and learning styles, namely auditory, kinesthetic, and visual. The type of research used is Research and Development (R&D) using the ADDIE development model, namely Analyze, Design, Develop, Implement, and Evaluate. The subjects used were 35 students of class XI-3 at SMA Negeri 2 Kuningan. Data collection techniques used questionnaires, interviews, and tests. The instruments used were validation and practicality questionnaire sheets, interview guidelines, and mathematical problem solving ability tests. Data sources were obtained from lecturers, teachers, and students. Data were obtained from the validation results of material experts, media experts, teacher practicality, student practicality, and pre-test and post-test questions. Data analysis techniques used include validity test, practicality test, and N-Gain test. The validity of E-LKPD was tested by three material expert validators and two media experts. The validation results from the three material experts obtained a percentage of 90%, indicating that E-LKPD is very valid. The validation results from the two media experts obtained a percentage of 86%, indicating that E-LKPD is very valid. The practicality of E-LKPD was tested by teachers and students. The results of the practicality test using a questionnaire from teachers obtained a percentage of 93% indicating that E-LKPD is very practical, while the percentage from students was 88% with a very practical category. This shows that the E-LKPD that has been developed is very practical. The results of the N-Gain test obtained an average value of 0.78 which is categorized as high. Flipbook-based E-LKPD in differentiated learning on circle material is said to be valid, practical and can improve students' mathematical problem-solving abilities. Suggestions for further researchers in the development of E-LKPD can use other platforms or applications such as wizer.me which can facilitate students in answering E-LKPD.
Keywords: Circles, Differentiated Learning, E-LKPD, Flipbook, Mathematical Problem Solving Skills.