The Effect of Numbered Heads Together and Teacher-Centered Learning on Students' Conceptual Understanding and Mathematical Reasoning in Systems of Linear Equations in Two Variables

Abstract

This study investigated the effect of the Numbered Heads Together (NHT) learning model compared with Teacher-Centered Learning (TCL) on students' conceptual understanding and mathematical reasoning in learning Systems of Linear Equations in Two Variables (SPLDV). The study employed a quantitative approach using a quasi-experimental design with a pretest–posttest non-equivalent control group design. The participants consisted of 40 eighth-grade students at MTs Al Washliyah Pematangsiantar, selected through cluster random sampling, with 20 students assigned to the experimental group and 20 students to the control group. Data were collected using conceptual understanding and mathematical reasoning tests that had been validated and tested for reliability. Data analysis was conducted using descriptive statistics and Multivariate Analysis of Variance (MANOVA) with IBM SPSS Statistics 26 at a significance level of 0.05. The results revealed a significant multivariate effect of the learning model on students' conceptual understanding and mathematical reasoning (Wilks' Lambda = .731, F = 6.817, p = .003). Follow-up analyses showed that the NHT model significantly improved conceptual understanding (F = 5.676, p = .022) and mathematical reasoning (F = 12.054, p = .001) compared with Teacher-Centered Learning. Students in the NHT group also achieved higher mean scores on both learning outcomes than those in the TCL group. These findings indicate that the Numbered Heads Together learning model is more effective than Teacher-Centered Learning in enhancing students' conceptual understanding and mathematical reasoning in learning SPLDV. Therefore, NHT can be recommended as an effective student-centered instructional strategy to support mathematics learning and the implementation of the Merdeka Curriculum.