Edumatika : Jurnal Riset Pendidikan Matematika

The Interaction between Mathematical Problem-Solving Skills and Mathematical Communication Skills of Junior High School Students: A Qualitative Approach

Hamdani Syaputra — 2025-11-03

Mathematical problem-solving skills (MPSS) and mathematical communication skills (MCS) has a very close relationship. Before solving a problem, students should understand the problem first, processing and presenting their answer, which is a MCS. Different from the previous study, this study reveal the relationship and interaction between students’ MPSS and MCS using a qualitative approach. To do this, a case study method is conducted using valid test and interviews. The test consist of three cases: smartphone storage, riddle about number of chickens and the coop, and area of land to be planted with corn. The participants of this study were eighth-grade 18 students from various junior high scholl and region in West Sumatra. Data analysis used is a descriptive analysis of students' test answers and interview results. The results show that there are five of nine interactions between MPSS and MCS: solver, self-solver, sharer, regular, and receiver. Solver is a student with high MPSS and MCS (2 students), self solver is a student with high MPSS but moderate MCS (6 students), sharer is a student with moderate MPSS but high MCS (4 students), regular is a student with moderate MPSS and MCS (3 students), and receiver is a student with low MPSS and MCS (3 students). The results of this study also show that the relationship between MPSS and MCS is very close. Although there are students who have MPSS and MCS that do not match, this is inseparable from the limitations of the research conducted.

Exploring of Ethnomathematics in the Local Culture of North Karawang Coastal Fishermen for Elementary School Mathematics

Diah Pitaloka — 2025-11-08

This research aims to explore the activities of fishermen on the coast of Sungai Buntu Beach, Karawang, that contain mathematical concepts, and to map them into the learning outcomes of phases A–C at the primary school level. A qualitative approach with an ethnographic design was used, through observation, interviews, and documentation. The data were then analysed with data reduction, presentation, and conclusion drawing, and their validity was tested through triangulation. The results show that fish trading activities contain number concepts; calculating the catch in a basket reflects algebra through variables and simple equations; the salting and weighing of fish emphasise measurement, proportionality, and capacity; the shapes of boats, nets, baskets, drying racks, and fish crates demonstrate the application of geometric concepts in 2D and 3D shapes; and seasonal catch patterns, trading transactions, and the salting of dried fish provide a context for data analysis and probability. These findings affirm that the cultural practices of fishermen in the North Karawang coastal area, particularly those in Sungai Buntu Beach can be used as an authentic source for contextual, relevant, and meaningful mathematics learning, and are also applicable to other coastal regions with similar cultural characteristics such as the North Coast of West Java, supporting the development of local culture-based teaching materials to enhance students' motivation, understanding, and learning outcomes.

Developing and Validating MCA-Equivalent Summative Assessment in Combinatorics Using Aiken’s V Method

Nurjihan Nabilah — 2025-10-30

This study aims to analyze the content validity of summative assessment items in Combinatorics that are aligned with the Minimum Competency Assessment (MCA) framework. The study was motivated by the need for valid and high-quality assessment tools that support meaningful and sustainable mathematics learning. This study employed a research and development (R&D) design but it focuses primarily on the Develop stage, which aims to obtain a valid summative assessment instrument. The Aiken’s V method was used to measure the content validity of nine multiple-choice items developed according to the MCA numeracy domains, cognitive levels, and contexts. Three mathematics education experts served as validators. The analysis showed that the Aiken’s V indices ranged from 0.64 to 0.73, indicating medium validity. These results suggest that the instrument can be used after minor revisions. The validated instrument provides a reference for educators to design MCA-oriented summative assessments that enhance students’ mathematical literacy and reasoning skills. Future research may apply other validation methods such as Gregory’s analysis to strengthen the evidence of validity.