• The Mathematical Education
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• v.62 no.1
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• pp.23-34
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• 2023

The rationalizing denominators presented in the mathematics textbooks is being used in various places of school mathematics curriculum. However, according to some previous research on the rationalizing denominators in school mathematics, it seems that there is no clear explanation as to why rationalizing denominators is necessary and why it should be used. In addition, a previous research insists that most students know how to rationalize denominators but do not understand why it is necessary and important. To confirm this, we examined the rationalizing denominators presented in the 2015 revised mathematics curriculum as school mathematics. Then we also examined the rationalizing denominators algebraically as academic mathematics. In detail, we conducted an analysis on the rationalizing denominators presented in randomly selected three mathematics textbooks and teacher guidebooks for middle school third grade. Then the algebraic meaning of the rationalizing denominators was examined from a proper algebraic structure analysis. Based on this, we present alternative definitions of the rationalizing denominators which is suitable for school mathematics and academic mathematics. Finally, we also present the mathematical contents (irrationals of the special form can be algebraically interpreted as numbers in the standard form) that teachers should know when they teach the rationalizing denominators in school mathematics.

• Journal of Digital Contents Society
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• v.5 no.4
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• pp.289-294
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• 2004

For the purpose of image analysis, we usually take the application method relying on the various mathematical theories. On the respect of image as two variable function one may uses the gradient vector or several type of energy functions induced by the conventional (partial) derivative. We also have used the tangent plane or curvature vector from the concept of differential geometry {**]. However, these mathematical tools my assume that the given function should be sufficiently smoothing enough to depict every local variation continuously. But the real application of these mathematical methods to the natural images or phenomena may occur the ill-posed problem. In this paper, we have defined the weak derivative as a loose form of the derivative so that it my applied to the irregular case with less ill-posed problem.

• Journal of the Korean School Mathematics Society
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• v.22 no.2
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• pp.95-113
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• 2019

In this paper, we analyzed the levels of cognitive demand of the tasks for developing t he mathematical core competencies presented in the "Mathematics" textbook of the first y ear of high school developed according to the 2015 revised mathematics curriculum. "Mathematics" textbook included 4999 mathematics tasks, of which 703 were tasks for developing the mathematical competency. Analysis of 703 mathematical tasks according to the analysis framework of Stein, Smith, Henningsen, and Silver (2000) showed that 61.5% of students required high cognitive levels, 38.5% required low cognitive levels, and the types of tasks were as follows: Low-M 1.0%, Low-P 37.5%, High-P 57.8%, High-D 3.7%. It w as found that most of the tasks for the purpose were tasks that led to understanding mathematical concepts, principles, and processes along procedural processes.

• Journal of Educational Research in Mathematics
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• v.20 no.4
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• pp.529-546
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• 2010

This study aims to analyze and criticize the definition of the similarity concept in mathematical texts by investigating mathematical history. At first, we analyzed the definition of Pythagoras, the definition of Euclid's ${\ll}$Elements${\gg}$, the definition of Clairaut's ${\ll}$Elements of geometry${\gg}$, the postulate of Brkhoff's postulates for plane geometry, the definition of Birkhoff & Beatly의 ${\ll}$Basic Geometry${\gg}$. the definition of SMSG ${\ll}$Geometry${\gg}$. and the definition of the similarity concept in current mathematics texts. Then we criticized the definition of the similarity concept in current mathematics texts based on mathematical history. We critically discussed three issues and gave three suggestions.

• Education of Primary School Mathematics
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• v.26 no.4
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• pp.257-275
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• 2023

In this study, we designed and implemented a instruction emphasizing mathematical argument for fifth-grade students and analyzed the teaching practices. Through a literature review related to instruction emphasizing mathematical argument, we organized a teaching model of five phases that explain why the general claim that the sum of consecutive odd numbers equals a square number is true: 1) noticing patterns, 2) articulating conjectures, 3) representing through visual model, 4) arguing based on representation, 5) comparing and contrasting. Then, we analyzed the argumentation stream by phases to observe how the instruction emphasizing mathematical argument is implemented in the elementary classroom. Based on the results of this study, we discuss the implications of teaching a mathematical argument in elementary school.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2009.05a
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• pp.101-106
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• 2009

수학적 사고의 입장에서 중등학생들이 수학적 문제해결에 논리적 사고와 직관적 사고가 어떻게 작용하는지를 연구하는 것은 수학교육에서 중요하고도 흥미로운 과제의 하나이다. 본 연구의 주된 목적은 중등학교 영재학생을 대상으로 이러한 문제를 조사하는 것이다. 특히 이들 중등영재학생들의 논리적 사고와 직관적 사고에 대한 선호도와 논리적 문제의 문제해결능력 사이의 관계를 조사한다.

• Journal of Educational Research in Mathematics
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• v.17 no.4
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• pp.395-418
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• 2007

The purpose of this study was to analyze the influence of mathematical tasks on mathematical communication. Mathematical tasks were classified into four different levels according to cognitive demands, such as memorization, procedure, concept, and exploration. For this study, 24 students were selected from the 5th grade of an elementary school located in Seoul. They were randomly assigned into six groups to control the effects of extraneous variables on the main study. Mathematical tasks for this study were developed on the basis of cognitive demands and then two different tasks were randomly assigned to each group. Before the experiment began, students were trained for effective communication for two months. All the procedures of students' learning were videotaped and transcripted. Both quantitative and qualitative methods were applied to analyze the data. The findings of this study point out that the levels of mathematical tasks were positively correlated to students' participation in mathematical communication, meaning that tasks with higher cognitive demands tend to promote students' active participation in communication with inquiry-based questions. Secondly, the result of this study indicated that the level of students' mathematical justification was influenced by mathematical tasks. That is, the forms of justification changed toward mathematical logic from authorities such as textbooks or teachers according to the levels of tasks. Thirdly, it found out that tasks with higher cognitive demands promoted various negotiation processes. The results of this study implies that cognitively complex tasks should be offered in the classroom to promote students' active mathematical communication, various mathematical tasks and the diverse teaching models should be developed, and teacher education should be enhanced to improve teachers' awareness of mathematical tasks.

• Journal of the Korean School Mathematics Society
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• v.13 no.1
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• pp.1-21
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• 2010

This paper analyzed the contents and instructional methods of various plane figures presented mainly in a series of elementary mathematics textbooks on the basis of the analysis of related contents in the 2007 revised national mathematics curriculum. As such, this paper provided detailed analyses of how textbooks would implement the vision and intention of the curriculum, how the definition of each plane figure in the textbooks might be different from its mathematical definition, and how textbooks would introduce each plane figure. It is expected that the issues and suggestions stemming from this analysis will be informative in designing new instructional materials.

• Communications of Mathematical Education
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• v.30 no.1
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• pp.67-83
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• 2016

Correcting an imbalance between cognitive and affective aspects of mathematics in schools is recognized as a crucial issue with regards to mathematics education in Korea. Therefore, research and studies about affective aspects have been increasing and themes relating to affective aspects were diverse. Their theme included the improvement of affective aspect, investigation of factors of affective aspect, and development of measurement tools for affective aspect. The purpose of this study is to analyze and organize the research that has been done with respect to affective aspect and drive trend, implication, and their instruction to mathematics education. This study has investigated 103 studies released from 2005 to 2015 on KCI, Korea Citation Index. The results of this study are as follow. First, since released research of affective aspects in mathematics has not increased in number in the last 11 years, academic interest in the affective aspects seems lower than recent interest arousing in Korea. Second, most studies utilized quantitative research as a tool to analyze phenomena and the cause and effect of affective aspects. Third, middle school students were the most common subjects of the studies, followed by elementary school students. Fourth, the studies had various themes such as analyzing the cause and effect of affective aspect, recognizing changes of affective aspects, and measuring affective aspects. The studies, especially, focused most on analyzing how to improve affective aspects by applying it to programs such as mathematic activities and solving mathematic problems. It is necessary for future research to have a long-term perspective and to provide a space for communication. Research should not only focus on how recognize affective aspects differently, which is based on its cultural background, but also to draw affective solutions from them.

• Communications of Mathematical Education
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• v.13 no.1
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• pp.265-274
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• 2002

이 프로젝트는 수학 수업 중 ‘추론’과 ‘증명’에 관련된 "문제해결과정"에 관심을 가지고, 처음 증명문제를 접하는 독일 7학년 학생들을 대상으로 문제해결능력에 필요한 요인들, 즉, 문제 해결을 위한 수학적 기본지식, 해결된 문제에 대한 인지정도, 논리적 사고 등을 관찰 분석하고 수학교사의 수학에 대한 신념(Beliefs)과 수업 방식이 학생들의 문제해결에 미치는 영향을 조사하는 것에 그 목적을 둔다. 이 프로젝트의 일부의 결과로써, 본 논문에서는 학생들 개개인의 문제해결과정과 그 능력, 그리고 수학에 대한 신념을 서술하고, 수학교사와 학생들의 서로 다른 수학에 대한 신념을 비교 분석한다.