This research is based on the students do not have comprehensive understanding on circumference and area of square as the students faced learning obstacles while learning the concept of circumference and area of square. The purpose of this study is to overcome the learning obstacle faced by the students. The research method used in this research is Didactical Design Research (DDR) method which consists of three stages, namely the didactic situation analysis before learning in the form of HLT and ADP; metapedadidactic analysis; retrospective analysis by linking the results of the didactic hypothetical situation analysis with the results of the analysis of the metapedadidactic. Data collection techniques used triangulation techniques (observation, interviews, and documentation studies). This study resulted in a learning design in the form of a circumference didactic and area of square based on Péclé traditional games in grade IV elementary school which can overcome the students learning obstacle.

This research is motivated by conditions in elementary schools that the material of equivalent fractions is still considered difficult to understand for students in grade IV SD/MI because students previously only studied whole numbers such as numbersnatural and whole numbers, then study equivalent fractions as numbers that are divided in different forms but have the same value. This abstract subject matter requires a media that can visualize equivalent f ractional material, including through pictures. This study aims to develop multimedia-based equivalent fraction media in mathematics learning in grade IV SD/MI. This study uses the Design Based Research (DBR) method, with steps to identify and analyze problems, product design, product validation tests, product revisions, product trials. while the data were collected through interviews, study documentation, expert validation, the product was validated by material experts and media experts. the collected data is analyzed by reducing it, then the data is presented in the form of a brief description and chart, and confirmability test (objective) is carried out to test the validity of the product. in the first trial stage, 24 students of SDN II Sukakarsa were conducted, with a response result of 96% of students agreeing to use multimedia -based fractional media.

This research is inspired by the preliminary study that showing learning obstacles experienced by the students in comprehending square circumference concept. The students do not have total comprehension in understanding the square circumference because their low comprehension when studying it for the first time. It becomes the main background in solving the square circumference problems. It is required to create learning design to solve the problems. The researchers create a didactic design based on PetakUmpet traditional game in order to help the students to understand square circumference concept and also to preserve traditional cultures. Research methodology is using Didactical Design Research(DDR) with three level of analysis, there are: prospective analysis, metapedadidacticanalysis and retrospective analysis. Data collection technique is using triangulation (interview, observation and documentation). This research produces a teaching media as learning design in the form of lesson plan developed as an alternative learning design that can be used on square circumference concept in elementary school.

Penelitian ini dilatarbelakangi oleh kurangnya komunikasi matematis siswa khususnya dalam pembelajaran matematika. Model pembelajaran berbasis teori Van Hiele ini dapat digunakan dalam mengatasi permasalahan tersebut. Seperti, minimnya kosakata siswa dalam menerjemahkan kalimat matematika menggunakan bahasa sendiri, serta terbatasnya kemampuan komunikasi siswa dalam pelajaran geometri. Tujuan penelitian ini adalah untuk mengetahui pengaruh model pembelajaran berbais teori Van Hiele terhadap pembelajaran matematika di Sekolah Dasar.  Penelitian ini menggunakan metode Systematic Literature Review dengan mengumpulkan 80 jurnal yang relevan dengan penelitian ini kemudian diseleleksi kembali. Alasan pembelajaran berbasis teori Van Hiele dapat meningkatkan kemampuan komunikasi matematika yaitu (1) Pada setiap tahapan pembelajaran Van Hiele siswa diharuskan untuk aktif dalam memberikan pendapat, ide, atau gagasan siswa dengan argumen yang tepat sesuai dengan logika. (2) Pada tahap pembelajaran Van Hiele tepatnya pada tahap informasi guru mengidentifikasi apa yang diketahui siswa tentang topik yang akan dipelajari melalui komunikasi antara guru dan siswa terdapat aktivitas dan percakapan mengenai objek yang diamati. Dengan menggunakan model pembelajaran berbasis teori Van Hiele ini dapat terlihat tingkat berpikir siswa terhadap materi geometri sudah sejauh mana serta dapat menciptakan pembelajaran yang lebih aktif dalam mengungkapkan ide atau gagasannya menggunakan bahasa sendiri. Berdasarkan studi literatur yang sudah dilakukan menggunakan sejumlah artikel yang relevan dan telah melalui proses seleksi, model pembelajaran berbasis berbasis teori Van Hiele terbukti dapat meningkatkan kemampuan komunikasi matematis siswa.

This study aims to describe the learning barriers experienced by students in material around square. This study uses qualitative method, with data collection used the form of interviews, observations, and instrument test questions as many 5 questions that have been validated by experts. The research subjects were 7 students and 1 fourth grade teacher at SDN 1 Sindangrasa. Creating an optimal learning process does not only focus on mastering the material possessed by the teacher, however, it must also attention to learning barriers experienced by students, students are able to understand the material as a whole. Based on the results the study, students experienced 4 types learning obstacles in the rectangular perimeter material, learning obstacle type 1 related to students' difficulties in understanding the concept of flat square shape, learning obstacle type 2 related to students' lack of understanding in the concept of the square circumference formula, type 3 learning obstacle student difficulties perimeter of square, learning obstacle type 4 students' incomprehension in completing stories related the perimeter of the square. There are 3 factors cause students experience learning barriers including ontogenic barriers (students' readiness to learn), didactic barriers (teachers' didactic aspects) and epistemological barriers (student knowledge has limited context).