Proses pembelajaran yang masih menggunakan metode konvensional dan kurang tersedianya bahan ajar merupakan salah satu penyebab rendahnya kemampuan pemecahan masalah matematis peserta didik. Tujuan penelitian ini untuk mengembangkan E-LKPD berbasis liveworksheets pada materi barisan dan deret yang valid, praktis, dan dapat meningkatkan kemampuan pemecahan masalah matematis. Prngrmbangan E-LKPD ini menggunakan model pembelajaran Problem Based Learning (PBL). Penelitian ini menggunakan jenis penelitian dan pengembangan atau Research and Development (R&D) dengan model pengembangan Plomp yang terdiri dari tiga fase, yaitu fase pendahuluan (preliminary phase), fase pembuatan prototipe (prototipe phase), dan fase penilaian (assessment phase). Penelitian ini dilakukan di SMK Taufiq Mubarok dengan subjek yang digunakan yaitu sebanyak 16 peserta didik kelas X jurusan Layanan Perbankan. Instrumen penelitian yang digunakan yaitu lembar validasi ahli, lembar kepraktisan guru dan peserta didik, serta soal tes pemecahan masalah. E-LKPD ini divalidasi oleh dua validator ahli materi dan dua validator ahli media. Hasil validasi ahli materi dan media masing-masing diperoleh nilai rata-rata persentase sebesar 93,06% dan 90,18% dengan kriteria sangat valid. Hasil kepraktisan guru dan peserta didik terhadap E-LKPD masing-masing diperoleh nilai rata-rata sebesar 96,43% dan 87,21% dengan kriteria kepraktisan sangat praktis. Hasil uji N-Gain diperoleh nilai rata-rata sebesar 0,81 dengan kriteria peningkatan tinggi. Hasil akhir penelitian pengembangan diperoleh produk berupa E-LKPD berbasis liveworksheets pada materi barisan dan deret yang valid, praktis, dan dapat meningkatkan kemampuan pemecahan masalah matematis peserta didik. Adapun saran untuk penelitian selanjutnya yaitu diharapkan dapat melakukan proses pembelajaran dan E-LKPD yang dikembangkan diaplikasikan sebagai bahan ajar.

The learning process that still uses conventional methods and the lack of availability of teaching materials is one of the causes of students' low mathematical problem solving abilities. The aim of this research is to develop E-LKPD based on live worksheets on sequences and series material that is valid, practical, and can improve mathematical problem solving abilities. This E-LKPD development uses the Problem Based Learning (PBL) learning model. This research uses a type of research and development (R&D) with the Plomp development model which consists of three phases, namely the preliminary phase, the prototype phase, and the assessment phase. This research was conducted at Taufiq Mubarok Vocational School with the subjects used were 16 class X students majoring in Banking Services. The research instruments used were expert validation sheets, teacher and student practicality sheets, and problem solving test questions. This E-LKPD was validated by two material expert validators and two media expert validators. The validation results from material and media experts respectively obtained an average percentage value of 93.06% and 90.18% with very valid criteria. The practicality results of teachers and students regarding E-LKPD respectively obtained an average score of 96.43% and 87.21% with very practical practicality criteria. The N-Gain test results obtained an average value of 0.81 with high gain criteria. The final result of the development research was a product in the form of an E-LKPD based on live worksheets on sequences and series material that is valid, practical, and can improve students' mathematical problem solving abilities. The suggestion for further research is that it is hoped that the learning process can be carried out and the E-LKPD that is developed can be applied as teaching material.