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All Journal Jurnal PAJAR (Pendidikan dan Pengajaran) Mitra Mahajana: Jurnal Pengabdian Masyarakat Rangkiang Mathematics Journal Jurnal Edukasi dan Penelitian Matematika
Zulhafendi, Redy Williantama
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Agriculture, Biological Sciences & Forestry Computer Science & IT Decision Sciences, Operations Research & Management Education Industrial & Manufacturing Engineering Mathematics Public Health Social Sciences Other

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KATEGORI KEMAMPUAN PESERTA DIDIK DALAM MENYELESAIKAN PERSOALAN TRISEKSI SUDUT ZAMAN THALES-EUCLID Zulhafendi, Redy Williantama
Jurnal Edukasi dan Penelitian Matematika Vol 13, No 3 (2024): September
Publisher : Departemen Matematika

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/jepm.v13i3.16355

Abstract

Angle trisection is a geometry concept that refers to the splitting of an angle into three equal parts, so that each part formed has the same angle size. This angle trisection became one of the three most interesting and unsolved mathematical problems during the last three centuries BC. Consequently, the purpose of this study is to examine the history of angle trisection in the Thales-Euclid era and measure students' ability to solve angle trisection problems. This research is a qualitative research that uses case study and literature review methods with data collection techniques through tests and interviews. The research subjects were selected by purposive sampling method from three high school students. Furthermore, the data obtained were analyzed descriptively and qualitatively with triangulation techniques. The purpose of this analysis is to ensure that the data obtained from various sources are valid. The results showed the extent of students' understanding in responding and creating how to solve this angle trisection using a ruler and a period. A detailed presentation of the categories of answers given by learners will be presented in this paper.Keywords–Angular Trisection, Thales-Euclid Era, History of Mathematics
SOSIALISASI DAN STRATEGI JITU PENCEGAHAN PERGAULAN BEBAS DI SEKOLAH DASAR NAGARI 19 KOTO BARU Noveria, Ena; Zulhafendi, Redy Williantama; Fadillah, Muhammad; Hariman, Subhan Nuredi; Hadi, Irfan Surya; Nadiroha, Widia
Mitra Mahajana: Jurnal Pengabdian Masyarakat Vol. 6 No. 1 (2025): Volume 6, Nomor 1 Maret 2025
Publisher : LPPM Universitas Flores

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37478/mahajana.v6i1.5419

Abstract

Promiscuity is an increasingly worrying social phenomenon, including among elementary school children. The socialisation of promiscuity prevention at the elementary school level is crucial for building a strong character foundation from an early age. This study aims to improve students' understanding of promiscuity and identify effective strategies for preventing promiscuity in elementary school children. The qualitative research method involved all students at SDN 19 Koto Baru. Data was collected through observation and questioning and analysed using thematic and meta-review methods. The results showed that the majority of students had gained basic knowledge about the dangers of promiscuity, although there were still concerns about peer pressure. These findings provide an important insight for strengthening character education programmes in schools and supporting the role of the family in preventing deviant behaviour from an early age. Therefore, this study recommends that teachers optimise interactive teaching methods, parents increase dialogue and supervision at home, and schools routinely organise socialisation programmes to create a positive social environment conducive to forming strong moral values.
Improving Mathematical Reasoning Through Geogebra-Assisted Discovery Learning Zulhafendi, Redy Williantama; Yarman
Jurnal PAJAR (Pendidikan dan Pengajaran) Vol. 10 No. 2 (2026): March
Publisher : Laboratorium Program Studi Pendidikan Guru Sekolah Dasar

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33578/pjr.v10i2.385

Abstract

This study aims to improve the mathematical reasoning ability of Grade XI students through the implementation of GeoGebra-assisted discovery learning. The research employed a classroom action research design conducted in two cycles, each consisting of the stages of planning, implementation, observation, and reflection. The participants were 40 Grade XI students at SMA Negeri 8 Padang, and the learning material focused on geometric transformations. The main research instrument was an essay test developed based on indicators of mathematical reasoning ability. Data were analyzed by examining the average test scores and learning completeness in each cycle. The results showed that the application of GeoGebra-assisted discovery learning successfully improved students’ mathematical reasoning skills. This improvement was indicated by an increase in the average test score from 63.15% in Cycle I to 81.22% in Cycle II. In addition, learning completeness increased from 55% in Cycle I to 80% in Cycle II, thereby meeting the predetermined success indicator of at least 70% of students achieving improvement. Discovery-based learning supported by GeoGebra encouraged students to actively observe patterns, formulate conjectures, examine arguments, and draw conclusions through direct visual exploration. These findings suggest that the integration of technological media into active learning models can foster deeper, more logical, and more structured mathematical reasoning processes. Therefore, GeoGebra-assisted discovery learning is effective in enhancing the mathematical reasoning ability of Grade XI students.
Analysis of Students' Errors Based on Newman's Errors in Solving Mathematical Reasoning Problems Zulhafendi, Redy Williantama; Yerizon, Yerizon; Dwina, Fitrani; Sari, Shinta
Rangkiang Mathematics Journal Vol. 5 No. 1 (2026): Rangkiang Mathematics Journal
Publisher : Department of Mathematics, Universitas Negeri Padang (UNP)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/rmj.v5i1.91

Abstract

Mathematical reasoning is one of the essential competencies that students must possess to face the challenges of 21st-century learning. However, many students still struggle to solve problems that assess their mathematical reasoning. This study aims to analyse the types of errors students make using Newman’s Error Analysis procedure. The research employed a descriptive qualitative method, with 37 twelfth-grade high school students selected through purposive sampling. Data were collected through a mathematical reasoning ability test and interviews. The quantitative data from the test were analysed descriptively to identify error patterns, while the qualitative data from interviews were analysed thematically through data reduction, data display, and conclusion drawing. Most students made errors in three main stages, namely understanding the problem concept, transforming verbal information into appropriate mathematical representations, and applying mathematical procedures or algorithms correctly. Furthermore, the analysis showed that conceptual misunderstanding was the most prevalent type of error, often leading to subsequent transformation and process-skill errors. These findings suggest that teachers need to design learning interventions that strengthen conceptual comprehension and develop students’ systematic problem-solving strategies.
Co-Authors Dwina, Fitrani Ena Noveria Fadillah, Muhammad Hadi, Irfan Surya Hariman, Subhan Nuredi Nadiroha, Widia Sari, Shinta Yarman Yerizon Yerizon