Tujuan penelitian untuk mengembangkan LKPD Matematika berbasis Problem Based Learning Materi FPB dan KPK kelas V Sekolah Dasar. Pengembangan LKPD Matematika dilatarbelakangi oleh kebutuhan pembelajaran yang dapat meningkatkan kemampuan peserta didik dalam pemecahan masalah, kemampuan dalam berfikir kritis serta menumbuhkan rasa ingin tahu. Jenis penelitian ini adalah penelitian pengembangan (research and development/R&D). Tahapan utama dalam penelitian dan pengembangan ini adalah (1) pengumpulan informasi dan penelitian pendahuluan; (2) perencanaan; (3) pengembangan produk; (4) pengujian terbatas, dan (5) revisi produk akhir. Populasi dalam penelitian ini adalah pendidik kelas V SD Negeri kecamatan Tegineneng. Teknik pengambilan sampel yang digunakan adalah teknik purposive sampling. Sampel penelitian adalah 3 (tiga) guru kelas V SDN 28 Tegineneng, SDN 20 Tegineneng, dan SDN 1 Tegineneng. Teknik pengumpulan data menggunakan observasi dan angket. Teknik analisis data dalam penelitian ini menggunakan teknik analisis deskriptif kualitatif. Berdasarkan hasil penelitian dan pembahasan dapat disimpulkan bahwa pengembangan materi LKPD berbasis PBL di Sekolah Dasar sangat layak untuk digunakan dalam pembelajaran. Hal tersebut berdasarkan hasil validasi ahli materi sebesar 92,17%, hasil validasi ahli desain sebesar 86,67%, hasil validasi ahli media sebesar 89,56% dan hasil tes kepada guru sebesar 92,13%.

This study is a quasi-experimental research with pretest-posttest control group design, which aims to determine (1) the tendency of students in using various media scaffolding based on gender, and (2) effect of media scaffolding on increasing understanding of students' geometry concepts. Media scaffolding used this study is chart, props, and visual. The population was the fifth grade students of State Elementary School I Gunung Terang (total 40 students), Bandar Lampung, Indonesia of the academic year 2015-2016. The sample was total sampling, respectively 20 students in the experimental class (with media scaffolding) and control class (without media scaffolding). Data were collected through observation, interview and test. Analysis of the observation and interviews data with descriptive statistics (percentage). and the test data was analyzed by (a) measuring the level of effectiveness on increasing understanding of students' geometry concepts with formula of Hake's Normalized Gain (g) and its interpretation, and (b) examine of hypotesis on level of effectiveness with t-test. The results of research showed that (1) the tendency of male students using the media scaffolding props, and female students using scaffolding media chart, and (2) effect of media scaffolding on increasing understanding of students' geometry concepts is effective enough.

In this context, several recent studies have focused on the ability to understand a problem and difficulties regarding the solving as a means of improve students' mathematical problem-solving abilities. Design of research explores types and factors of mistakes students in solving mathematical problems. The instrument used is problem solving test. Data from Indonesia secondary school students (N = 147) who were about 15 years old were analyzed using theory Newman. Procedure Newman includes: reading errors, comprehension errors, transformation errors, process skill errors and enconding errors. The results indicate to reading errors of 4.35%, comprehension errors of 17.39%, transformation errors of 34.78%, process skill errors of 23.91%, and enconding errors 19.57%. Factors errors students' is not to absorb information well, not understanding the transformation of the problem, not following the material thoroughly, and comprehension mathematical of weak concepts.

The ability of reversible thinking in mathematics has less attention, but most of the mathematical subject is reversible. This type of research was qualitative descriptive which aimed to analyze student’s reversible thinking skills on the graph concept. The subject of research were students of mathematics education, Faculty of Teacher Training and Education, Lampung University taking the graph theory in the academic year 2019/2020. Research subjects were 40 people selected by the total sampling technique. The research data was collected through tests, namely the question of Ramsey number. Data were analyzed descriptively with 3 stages, namely data reduction, data display, and conclusion. The results showed that 42.5% of students had reversible thinking skills and 57.5% of students did not have them. Based on the results of this study, it was concluded that most students did not have reversible thinking skills on graph concepts.

Tujuan penelitian ini adalah menghasilkan media pembelajaran interaktif yang terintegrasi soft skills untuk meningkatkan kemampuan pemecahan masalah siswa yang valid dan praktis. Penelitian ini merupakan penelitian pegembangan yang menggunakan model pengembangan ADDIE (Analysis, Design, Development, Implementation, dan Evaluation. Subjek penelitian pada tahapan implementasi adalah siswa kelas V SDIT Muhammadiyah Gunung Terang Bandar Lampung Tahun Pelajaran 2019-2020. Data penelitian dipeoleh dari observasi, wawancara, angket respon guru dan siswa terhadap media pembelajaran. Hasil penelitian menunjukkan bahwa media pembelajaran interaktif yang dikembangkan sangat valid dengan skor dari validasi ahli materi sebesar 81% dan validasi ahli media sebesar 84%. Media pembelajaran ini juga dinyatakan praktis sebagaimana hasil uji praktisi mendapatkan skor sebesar 86% dan uji coba siswa sebesar 88%.