Union: Jurnal Ilmiah Pendidikan Matematika Volume 11(1), 2023, pp. 20-28 https://jurnal.ustjogja.ac.id/index.php/union DOI: 10.30738/union.v11i1.13723 © Author (s), 2023. Open Access This article is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License, which enables reusers to distribute, remix, adapt, and build upon the material in any medium or format, provided appropriate credit is given to the original author(s) and the source. The license allows for commercial use. If you remix, adapt, or build upon the material, you must license the modified material under identical terms. For more details and to view a copy of this license, visit https://creativecommons.org/licenses/by-sa/4.0/. Analysis of STAD model on students with low abilities in learning geometry Samsul Pahmi 1 *, Nanang Priatna 2 , Karina Yulianti 1 , Fitria Nurulaeni 1 , Akash Satish Kumar 3 1 Facultyof Business and Humanities, Nusa Putra University, Jl. Raya Cibolang No.21, Sukabumi 43152, West Java, Indonesia 2 Department of Mathematics Education, Universitas Pendidikan Indonesia, Jl Dr. Setiabudi No. 229, Bandung 40154, West Java, Indonesia 3 Hindustan Institute of Technology and Science, Rajiv Gandhi Salai (OMR), Padur, Kelambakkam, Tamil Nadu 603103, India * Corresponding Author. Email: samsul.pahmi@nusaputra.ac.id Received: 15 December 2022; Revised: 25 December 2022; Accepted: 28 December 2022 Abstract: This research is based on the mathematics learning outcomes of elementary school students which are still low in terms of student learning outcomes. The current study reveals that as many as 66.67% of students have not been able to achieve the minimum requirements, especially in the section of geometry; reflecting a need to improve mathematics learning outcomes. This gap in learning outcome is due to the fact that a majority of students tended to be passive during learning. The STAD learning model is a learning model that emphasizes student activities and interactions for learning mathematics in the classroom. The research design used in this study is a one group pretest posttest design. The sampling method used in the study was purposive sampling from a class of thirty elementary school students with issues related to mathematical abilities. Data collection techniques consist of primary sources in the form of tests, interviews, and observations, while secondary sources include documentation and literature studies. The data analysis technique used is the t-test (or using the Wilcoxon test if the data is not normally distributed), and the Gain Test. The results showed that there is a positive influence of STAD model on learning outcomes. Keywords: Geometry; Primary school, STAD learning model How to cite: Pahmi, S., Priatna, N., Yulianti, K., Nurulaeni, F., Kumar, A. S. (2023). Analysis of STAD model on students with low abilities in learning geometry. Union: Jurnal Ilmiah Pendidikan Matematika, 11(1), 20-28. https://doi.org/10.30738/union.v11i1.13723 INTRODUCTION Mathematics, a core subject considered as queen of sciences contains abstract concepts. This makes the topics such as algebra, calculus, and geometry difficult for most of the students, causing a decrease in involvement and skill among students. Experts categorize geometry as a topic requiring basic skill. Several studies reveal difficulties faced by teachers and students in teaching and learning mathematics, especially geometry. Students often fail to develop visualization and exploration skills necessary for geometric concepts, problem-solving skills, and geometric reasoning (Ngirishi & Bansilal, 2019). In order to describe the knowledge of geometry and the teaching of knowledge of geometry, many studies conducted in several countries have evaluated teachers' knowledge of mathematics subjects based on the general belief that the greater the knowledge of the subjects, the better the teaching (Schmidt et al., 2002; Mapolelo & Akinsola, 2015). In the case of geometry, knowledge of mathematics among teachers appears to be uneven with several gaps especially among elementary school teachers (Kuzniak & Rauscher, 2011; Depaepe et al.,