Turkish Journal of Computer and Mathematics Education

108-118

Authors: Yavuz Karpuz, Timur Koparan, Bülent Güven

In this study, we aim to investigate how students build interaction between concepts and figure in geometry. For this purpose we developed two type data collection tool. First one called shapely is formed eight open ended question which has concepts and figure. Second one called shapeless is formed eight open ended question which has only concepts. To prepare this data collection tools’ difficulty level we took two math teachers’ opinions. Developed data collection tools were applied 120 students at 9th grade and 11th grade in Trabzon Gazi Anatolian High School. First of all we applied shapeless questions. One month later we applied shapely questions. We investigated students’ answer and the data showed that students more succeed in shapely questions than shapeless questions. We concluded that the difficulty of solving shapeless question result from students didn’t manage to draw figure representing concept knowledge or draw wrong figure, figure drawn by students can’t fulfıl generalizability condition and students who have little knowledge of concept in geometry is under the influence of prototype figure.

137-157

Authors: Candaş Uygan, Dilek Tanışlı, Nilüfer Y. Köse

The purpose of this study is to research pre-service elementary mathematics teachers’ beliefs on meaning and features of mathematical proof, their proving processes and their reasoning process while evaluating validities of proof examples. This study is a qualitative research. Participants of the study are three pre-service elementary mathematics teachers who continue to study in a state university from Central Anatolia Region. Participants’ beliefs on proof were researched with semi-structured interview whilst proving processes and evaluation processes of proof examples were researched with clinical interviews. Interviews were recorded with video camera and data were analyzed according to qualitative methods. When beliefs on proof were analyzed, it was indicated that participants see mathematical proofs as problem solving process and exploration of source of mathematical knowledge, and believe that proofs have to be deductive, apprehensible and have to include generalizable results. Also according to opinions of all three participants, they believe that their proving abilities are insufficient. Analyze results related to proving processes indicated that pre-service teachers considered conclusions of theorems as if they are conditions of theorems and also used proving strategies uncomprehendingly in proving process. Finally, analyze results related to proof evaluation process indicated that participants assessed computer based experimental verifications as valid mathematical proofs and had mistakes when they evaluated warrants used in verifications that break axiomatical structure of proofs.

176-206

Authors: Adnan Baki, Funda Aydın Güç

The aim of this study is to identify misconceptions of nine grade students on the topic of repeating decimal numbers. Data were obtained from forty students through “Diagnostic Test of Repeating Decimal Numbers” including open-ended questions. Questions were prepared according to the classification of misconceptions as overgeneralization, overspecialization, mistranslation and limited conception. As a part of rational numbers unit the topic of “representation of repeating decimals” is introduced at 6, 7, 8 and 9 grades in our schools. In spite of this, findings of this study illustrate that even nine grade students still have some common misconceptions about this topic. Findings illustrated that most students’ misconceptions were based on overgeneralization. In addition to this students also shared the other categories of misconceptions as well.