Teachers use their content and pedagogical content knowledge for teaching algebra. For this reason, the examination of how teachers use this knowledge may help shed light on how students learn algebra, especially in determining why they usually have difficulties. The aim of the current study is to reveal what teachers know, and propose what they actually need to know for teaching the simplification and equivalence of algebraic expressions. The multiplecase study design was used for this study to compare and contrast the two middle school teachers’ lesson planning and instruction. The data corpus included lesson plans, actual instruction records, and postobservation interviews. Data analysis was conducted using the Mathematical Knowledge for Teaching (MKT) model. The findings indicated that both teachers had a lack of specialized content knowledge about mathematical representations such as algebra tiles. They did not use algebra tiles effectively and could not link algebraic and geometric representations that underlie the idea of multiplication. It was observed that both teachers generally used unknowns and variables interchangeably indicating the inadequacy of their common content knowledge. In the planning process, the two teachers were able to state the common misconceptions that the students generally had and the ways of addressing them. Through the cases of these two teachers, it was observed that teachers need to have a good conceptual mathematical understanding and also knowledge of students’ thinking in order to design effective lessons. Based on the findings, the types of knowledge that the teachers need to have are outlined and the theoretical and practical implications of the study are discussed.
Birincil Dil  en 

Konular  Sosyal 
Bölüm  Araştırma Makaleleri 
Yazarlar 

Tarihler 
Yayımlanma Tarihi : 13 Aralık 2019 
Bibtex  @araştırma makalesi { turkbilmat487243,
journal = {Turkish Journal of Computer and Mathematics Education (TURCOMAT)},
issn = {},
eissn = {13094653},
address = {},
publisher = {Türkbilmat Eğitim Hizmetleri},
year = {2019},
volume = {10},
pages = {588  616},
doi = {10.16949/turkbilmat.487243},
title = {Examining Two Middle School Mathematics Teachers’ Knowledge for Teaching Manipulation of Algebraic Expressions during Lesson Planning and Instruction},
key = {cite},
author = {Girit Yıldız, Dilek and Akyüz, Didem}
} 
APA  Girit Yıldız, D , Akyüz, D . (2019). Examining Two Middle School Mathematics Teachers’ Knowledge for Teaching Manipulation of Algebraic Expressions during Lesson Planning and Instruction. Turkish Journal of Computer and Mathematics Education (TURCOMAT) , 10 (3) , 588616 . Retrieved from https://dergipark.org.tr/tr/pub/turkbilmat/issue/50604/487243 
MLA  Girit Yıldız, D , Akyüz, D . "Examining Two Middle School Mathematics Teachers’ Knowledge for Teaching Manipulation of Algebraic Expressions during Lesson Planning and Instruction". Turkish Journal of Computer and Mathematics Education (TURCOMAT) 10 (2019 ): 588616 <https://dergipark.org.tr/tr/pub/turkbilmat/issue/50604/487243> 
Chicago  Girit Yıldız, D , Akyüz, D . "Examining Two Middle School Mathematics Teachers’ Knowledge for Teaching Manipulation of Algebraic Expressions during Lesson Planning and Instruction". Turkish Journal of Computer and Mathematics Education (TURCOMAT) 10 (2019 ): 588616 
RIS  TY  JOUR T1  Examining Two Middle School Mathematics Teachers’ Knowledge for Teaching Manipulation of Algebraic Expressions during Lesson Planning and Instruction AU  Dilek Girit Yıldız , Didem Akyüz Y1  2019 PY  2019 N1  DO  T2  Turkish Journal of Computer and Mathematics Education (TURCOMAT) JF  Journal JO  JOR SP  588 EP  616 VL  10 IS  3 SN  13094653 M3  UR  Y2  2019 ER  
EndNote  %0 Türk Bilgisayar ve Matematik Eğitimi Dergisi Examining Two Middle School Mathematics Teachers’ Knowledge for Teaching Manipulation of Algebraic Expressions during Lesson Planning and Instruction %A Dilek Girit Yıldız , Didem Akyüz %T Examining Two Middle School Mathematics Teachers’ Knowledge for Teaching Manipulation of Algebraic Expressions during Lesson Planning and Instruction %D 2019 %J Turkish Journal of Computer and Mathematics Education (TURCOMAT) %P 13094653 %V 10 %N 3 %R %U 
ISNAD  Girit Yıldız, Dilek , Akyüz, Didem . "Examining Two Middle School Mathematics Teachers’ Knowledge for Teaching Manipulation of Algebraic Expressions during Lesson Planning and Instruction". Turkish Journal of Computer and Mathematics Education (TURCOMAT) 10 / 3 (Aralık 2019): 588616 . 
AMA  Girit Yıldız D , Akyüz D . Examining Two Middle School Mathematics Teachers’ Knowledge for Teaching Manipulation of Algebraic Expressions during Lesson Planning and Instruction. Turkish Journal of Computer and Mathematics Education (TURCOMAT). 2019; 10(3): 588616. 
Vancouver  Girit Yıldız D , Akyüz D . Examining Two Middle School Mathematics Teachers’ Knowledge for Teaching Manipulation of Algebraic Expressions during Lesson Planning and Instruction. Turkish Journal of Computer and Mathematics Education (TURCOMAT). 2019; 10(3): 616588. 