Constructing mathematical reasoning and proof skills is challenging for all students. In Indonesia, students' abilities to apply reasoning and proof skills are closely observed under the Ministry of Education's new curriculum. Nevertheless, students' efforts to develop reasoning and proof may require more feedback on various mathematical tasks for the implementation of the new curriculum. Therefore, this study aims to investigate the extent to which students demonstrate reasoning and proof in solving mathematical questions. A mixed-methods approach was employed, using an embedded research designs to collect quantitative and qualitative data. This research employed simple random sampling to collect quantitative data from 384 tenth grade students through test questions. Six scripts were chosen for in-depth examination in the qualitative analysis. The findings revealed that students struggled to demonstrate reasoning and proof; they relied on validation through counterexamples to support their assertions, failing to establish relationships between premises and conclusions. Students' lack of understanding of underlying concepts resulted in low performance on reasoning and proof questions. From the findings, we suggest that teachers become aware of assigning tasks and exposing students to exercises related to reasoning and proof, to enhance their mathematical reasoning and proof abilities.
Hoon et al. (Tue,) studied this question.