The German national educational standards state explicitly that students should be enabled to successfully interact with dynamic geometry software. In a feasibility study on providing a standardized assessment instrument by digital means, in order to assess students' mathematical competencies, the implementation of a task with such a dynamic…

This article reports on the design and implementation of a didactic sequence in the frame of a design-based research study. The research aim is to test the hypothesis that affordances of dynamic geometry may support students' awareness of logical relationships between geometrical properties of constructed figures. We elaborate on the task design…

The present study aims to examine 8th grade students' proof writing and justification skills. The research was conducted using the document analysis method. The participants of the study consisted of 16 voluntary 8th grade students. The participants were determined according to the convenience sampling method. Data were collected with the…

The aim of the study informing this paper was to investigate pre-service teachers' (PSTs') approaches to task design, posing the research question: How do pre-service teachers respond when they are asked to design an exploratory task using GeoGebra for 8th grade students? The research study and this paper focus on the PSTs' design stories rather…

The aim of this study is to examine 8th grade students' Van Hiele geometry thinking levels, proof writing and justification skills. The research was carried out with sixteen eighth grade students of a private school in Sivas. Participants were selected based on an easily accessible sample. The data were collected from the students who participated…

We present a case study of proving by three 12-13-year-old students with different levels of mathematical giftedness. After analysing students' proofs, we conclude that: there was a relation on the consistency and the students' levels of mathematically giftedness, being the least consistent the student not mathematically gifted and the most…

In the present study, the effects of using dynamic geometry software in active learning framework on students' problem posing skills and their views about problem posing were examined. The participants consisted of 16 eighth-grade students. Data were collected by problem posing tests, open-ended questions, student diaries, and dynamic geometry…

We report findings from an investigation of one teacher's instruction as he guided students through the proofs of 21 theorems in a Grade 8 Honors Geometry course. We describe a routine involving four distinct phases, including Setting up the Proof and Concluding the Proof. Results from an end-of-course proof test are also presented to attest to…

Undoubtedly, one of the areas most affected by the COVID-19 pandemic process was educational activities. In this study, the 33 eighth graders of a public elementary school in Turkiye were observed for a six-week online learning period. The aim was to obtain whether any changes occur in their geometry attitudes during the process and to reveal…

In this paper, Harel and Sowder's proof schemes of taxonomy were applied for identifying eighth grade students' learning of proof and proofing. This study aimed to examine what kind of proof schemes are used in geometry and measurement learning areas and student's skills in giving proof and their opinions about proof. Qualitative methods were…

This study focused on improving students' learning mathematical of proofs and proving by using combinations of proof strategies that span different levels of understanding of proof structure; we refer to these as 'level-spanning proof-production strategies'. We analysed the level-specific proof-production strategies evident in the lessons and…

To encourage students' self-regulated learning at home, developing skills for textbook use to overcome learning-related impasses is crucial. This study examined the effects of providing mathematics class sessions that combined teacher instruction on appropriate textbook use with peer instruction, aimed at promoting students' spontaneity and…

The study aimed to investigate the mathematics achievement of eighth grade students on geometric transformation and geometric thinking levels. This research was carried out in the fall semester of 2018-2019. The sample was 88 students from two different middle schools in an urban area of Erzincan, Turkey. The survey model was used. The geometric…

The purpose of the study was to investigate the experiences and perceptions of middle school students about the flipped classroom applications used in geometry lessons. The research was designed as a case study. Data were collected through field notes, focus group interviews, and semi-structured interviews. The sample consisted of 26 eighth-grade…

To achieve adaptive learning, a dynamic assessment system equipped with a cognitive diagnosis was developed for this study, which adopts a three-stage model of diagnosis-intervention-assessment. To examine how this system influenced spatial geometry learning, the study used a quasi-experimental method to investigate student learning outcomes…