Turkish Journal of Computer and Mathematics Education

18-30

Authors: Karmelita Pjanic, Edin Liđan

A wide range of mathematical ideas could be used to develop and justify a formula for calculating the area of trapezoid. Those ideas lead to different strategies for finding out area of trapezoid that we classify in three groups: decomposing, enclosing and transforming strategies. Those strategies should be part of mathematics content knowledge for teaching. In this study we trace a change in structure of mathematics content knowledge of nine pre-service mathematics teachers as a result of using GeoGebra applets that visualize different approaches in finding out the area of trapezoid. We argue that engaging pre-service mathematics teachers to develop and justify formula for calculating the area of trapezoid using GeoGebra applets is a worth task that enhances pre-service mathematics teachers’ content knowledge for teaching. Our experiment confirmed that the use of Geogebra encourage pre-service mathematics teachers to uncover new ideas that lead them towards clearer justifications and easier way of proving formula for area of trapezoid.

47-67

Authors: Selahattin Arslan, Duygu Taşkın, Arzu Kirman Bilgin

One of the theories in didactical research is Guy Brousseau’s (1998) Theory of Didactical Situations in Mathematics (TDSM) that investigates how learning occurs. TDSM, which intends to understand, interpret and improve teaching and learning activities, defines three different learning situations. One of these situations is adidactical situation emphasizing learning of students as a result of their interaction with a Milieu. The aim of this study is to compare student achievement in adidactical situation designed as individual work with those designed as group work. To this end, an adidactical situation was designed to form the area formulas for parallelogram and trapezoid. The study was conducted with 60 students of 7th grade. Data was gathered by academic achievement test, observation and semi-structured interviews. Mixed methods research design was utilized. Descriptive analysis was used for the analysis of the qualitative data, and Mann Whitney U - Test was used for the analysis of the quantitative data. Results of the study shows that the students working individually in adidactical situations are more successful than the students working in group in adidactical situations.

93-116

Authors: Alattin Ural

The aim of this study is to investigate what kind of materials are used in which grades in order to improve psychomotor skills and the use of information technologies by students in the courses taught by mathematics teachers and how these materials are used; and to elicit the perceptions of these teachers on the use of these materials. Twenty two mathematics teachers (out of 25) working in 7 secondary schools were given a questionnaire form containing open ended questions and they were asked to write down the answers to those questions on the same form. The research was designed in the scanning model as a qualitative study. The data obtained from teachers were analyzed descriptively and samples from the data were presented categorically. It was observed that, regarding the psychomotor skills, a pair compass-ruler-protractor, dotted-isometric-graph paper, cutting-folding paper in geometry; fraction slips and algebra squares in algebra were the materials used respectively. The grades where these materials are used were 5, 6, 7, and 8 respectively. Regarding the use of information and communication technologies, it was observed that Morpa and Vitamin, the software developed by Turkish Ministery of Education was used to teach the subjects which contain shapes or animation; PowerPoint presentations to teach solid objects, fractals; and animations and videos on the internet to teach solid materials, triangles, fractals, patterns and decoration, equations and symmetry. These activities are used in the grades 8, 7, 6, 5 respectively. The teachers stated that the fact that information technologies and psychomotor skills are not used to the extent they should be stems from the lack of time, lack of computers, the overpopulated classes and the washback effect of the national exams.