• School Mathematics
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• v.12 no.1
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• pp.45-60
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• 2010

In school mathematics, gakdo(korean, ie angular measure in english) lost effectiveness as a term, on the other hand, an expression gak-ui-kugi(korean, ie size of angle in english) is prevalent these days. So it is necessary to accept this expression. It is necessary to specify in textbook that the size of angle rely on the degree of gap between two edges regardless of the length of edges. The content of curriculum manual and the content of textbooks must be reconciled. Random units for measuring the size of angle are not contained in textbooks. It can be possible, but it is not carried out actually. So, it is necessary not to require it in curriculum manual considering this circumstance. In curriculum manual, it is necessary to specify the role of 1-right angle as a standard unit, and situations to use it must be presented in textbooks. In cut-paste method of finding the sum of the size of three angles in a triangle and the sum of the size of four angles in a quadrilateral, keeping a straight angle and one rotation in mind, an explanation is based upon a premise that students know how to express the $180{^{\circ}}$ and $360{^{\circ}}$ in figure as a result. It is a leap of logic.

• Journal of Educational Research in Mathematics
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• v.19 no.4
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• pp.513-530
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• 2009

In this paper, We analyse the contents of the national mathematical curriculum, the handbook of the curriculum, and elementary school mathematics textbook for the elementary school grade 1-2 focusing on 'number sense'. At first, we identify the meaning and the elements of number sense through analysing studies which are related to number sense. Number sense includes understanding the meaning of number, operation, and estimation, and the ability of applying numbers, operation and estimation on the context. Number sense consists of the elements of the contents and the elements of the processes. Secondly, with the elements of number sense which we have identified, we analyse the contents of the national mathematical curriculum, the handbook of the curriculum, and elementary school mathematics textbooks, and then criticize the contents. We find some problems as a result of the analysis : the range of number sense is unclear, the word 'number sense' is not used consistently, the elements used are limited, and the contents of the textbook are materialized inconsistently and poorly.

• Journal of Educational Research in Mathematics
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• v.26 no.1
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• pp.121-141
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• 2016

In Korea where there is the national curriculum and teachers depend highly on textbooks, the school mathematics is based on curriculum and textbooks. Especially considering responsibility that textbooks should reflect the curriculum properly, it is necessary to analyze the connection of mathematics curriculum and textbooks in order to review and improve the quality of our mathematics education. This research analyzes the connection of curriculum and textbooks for 5~6 grades and aims to have some implications for revision of the textbooks when application of elementary mathematics textbooks based on the 2009 revised national curriculum is completed to all grades. Following the preceding research for 1~2 and 3~4 grades, this research sets 5~6 grades as a subject of analysis and has four contents of analysis; analysis of textbooks based on restructured achievement criteria, analysis of connections between unit objectives of textbooks and the reconstructed achievement criteria, analysis of textbooks related to mathematical terms and symbols, and analysis of textbooks related to mathematical process. The result of analysis has some implications to develop textbooks based on the 2015 revised national curriculum.

• Journal of Elementary Mathematics Education in Korea
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• v.19 no.1
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• pp.17-37
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• 2015

In this paper, we compared and analyzed the Korean National Mathematics textbooks of the 2007 amendment curriculum and the Harcourt Math in America focused on fractions and decimals. To summarize the results of the analysis are as follows. First, both textbooks introduce fractions to the meaning of parts-whole concept, but the Harcourt Math is stronger than that of Korean Mathematics textbooks in the concept of unit fractions as a generator of fractions. Second, the fractions can be considered trivial materials - a fraction representing 1 whole, a fraction with it's denominator is 1 - were more clearly represented in our US textbooks than those of our Korean textbooks. Third, in the introduction of the term relating to the fractions, Korea is a strong point of view of the classification of fractions than the point of view of representation in comparison with the case of the United States. Fourth, the equivalent fraction and equivalent decimal concepts were described more detail in the United States of textbooks than those of the case of Korean textbooks. Finally, the approaches of fraction and decimal concepts were introduced more mathematically in the case of the United States than those of the case of Korean textbooks.

• Journal of Elementary Mathematics Education in Korea
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• v.19 no.4
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• pp.485-499
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• 2015

In this paper, focusing on definitions of terms related to ratio (a:b, external ratio, internal ratio, percentage, proportion, bi-ui-gap(value of a:b)), elementary school mathematics textbooks of Korea and Japan are compared. We can find significant differences between Korean and Japanese textbooks. In Korean textbook, 'bi-yul' includes both of the internal ratio and the external ratio. In Japanese textbooks, the external ratio(amount of unit size) and the internal ratio(wariai) are defined independently. And a:b is set to a subconcept of the internal ratio. In addition, a:b and percentage are presented as methods to express the internal ratio. From these results, the following four implications for developing our mathematics textbooks can be presented as conclusions. First, it is necessary to limit the ratio to mean the internal ratio. Second, it is necessary to define connotatively the ratio as the internal ratio and to set it as a prior concept of a:b. Third, it is necessary to define 1% as the internal ratio 0.01. Fourth, it is necessary to define bi-ui-gap as a number for expressing a:b, when viewing a:b as the expression method of the internal ratio.

• Journal of Educational Research in Mathematics
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• v.19 no.3
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• pp.393-407
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• 2009

In this article the definition of similarity and its introduction in Korean middle school textbooks based on the 7th national curriculum are analysed critically. As a result four suggestions are presented. First, on the consideration that the contents related with similarity has been removed in the elementary school curriculum, the meaning of 'constant rate' needs to be understood through the rich experience of drawing enlarged/reduced figures when similarity is introduced in middle school, Second, there are two different ways in enlargement/reduction of figures and in the definition of similarity. Teachers have to keep the limitations of the two ways in mind. Third, the activity of drawing similar figures in enlarged/reduced squared paper needs to be practiced. Last, on 'the relation of similarity' which is in the definition of similarity, it has to be examined whether 'similarity' should be presented in the documents of the national curriculum as a term.

• School Mathematics
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• v.7 no.2
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• pp.103-121
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• 2005

This article compares and analyzes mathematics textbooks of North Korea, South Korea, China and Japan and draws meaningful ways for introducing the division algorithm of fractions. The analysis is based on the five contexts: 'measurement division', 'determination of a unit rate', 'reduction of the quantities in the same measure', 'division as the inverse of multiplication or Cartesian product', 'analogy with multiplication algorithm of fractions'. The main focus of the analysis is what context is used to introduce the algorithm and how much it can appeal to students. This analysis supports that there is a few differences of introducing methods the division algorithm of fractions among those countries and more meaningful way can be considered than ours. It finally suggests that we teach the algorithm in a way which can have students easily see the reason of multiplying the reciprocal of a divisor when they divide with fractions. For this, we need to teach the meaning of a reciprocal of fraction and consider to use the context of determination of a unit rate.

• Journal of Elementary Mathematics Education in Korea
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• v.18 no.1
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• pp.105-122
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• 2014

In this paper, fraction division algorithms in Korean elementary mathematics textbooks are analyzed as a part of the groundwork to improve teaching methods for fraction division algorithms. There are seemingly six fraction division algorithms in ${\ll}Math\;5-2{\gg}$, ${\ll}Math\;6-1{\gg}$ textbooks according to the 2006 curriculum. Four of them are standard algorithms which show the multiplication by the reciprocal of the divisors modally. Two non-standard algorithms are independent algorithms, and they have weakness in that the integration to the algorithms 8 is not easy. There is a need to reconsider the introduction of the algorithm 4 in that it is difficult to think algorithm 4 is more efficient than algorithm 3. Because (natural number)${\div}$(natural number)=(natural number)${\times}$(the reciprocal of a natural number) is dealt with in algorithm 2, it can be considered to change algorithm 7 to algorithm 2 alike. In textbooks, by converting fraction division expressions into fraction multiplication expressions through indirect methods, the principles of calculation which guarantee the algorithms are explained. Method of using the transitivity, method of using the models such as number bars or rectangles, method of using the equivalence are those. Direct conversion from fraction division expression to fraction multiplication expression by handling the expression is possible, too, but this is beyond the scope of the curriculum. In textbook, when dealing with (natural number)${\div}$(proper fraction) and converting natural numbers to improper fractions, converting natural numbers to proper fractions is used, but it has been never treated officially.

• Journal of Educational Research in Mathematics
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• v.13 no.3
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• pp.247-265
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• 2003

The purpose of this study is to analyze the essence of ratio concept from educational viewpoint. For this purpose, it was tried to examine contents and organizations of the recent teaching of ratio concept in elementary school text of Korea from ‘Syllabus Period’ to ‘the 7th Curriculum Period’ In these text most ratio problems were numerically and algorithmically approached. So the Wiskobas programme was introduced, in which the focal point was not on mathematics as a closed system but on the activity, on the process of mathematization and the subject ‘ratio’ was assigned an important place. There are some educational implications of this study which needs to be mentioned. First, the programme for developing proportional reasoning should be introduced early Many students have a substantial amount of prior knowledge of proportional reasoning. Second, conventional symbol and algorithmic method should be introduced after students have had the opportunity to go through many experiences in intuitive and conceptual way. Third, context problems and real-life situations should be required both to constitute and to apply ratio concept. While working on contort problems the students can develop proportional reasoning and understanding. Fourth, In order to assist student's learning process of ratio concept, visual models have to recommend to use.

• Journal of Educational Research in Mathematics
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• v.15 no.1
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• pp.39-56
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• 2005

This paper provides an analysis of a survey on high achieving students' under-standing of continuity of function. The purposes of the survey in this paper were to identify high achieving students' concept images of continuity of function in the way of Tall & Vinner(1981). The students' individual written answers were collected and task-based, semi-structured individual interviews with 5 students were videotaped. Students were asked to explain their under-standing or reasoning about continuity of function. Five types of the concept images were identified in the analysis. Obvious discrepancy of results between this study and Tall & Vinner(1981)'s were pointed out. It is very likely that the differences in results drawn in both studies are results of the different orientations of the textbooks in terms of their degree of emphasis on the concept definition of continuity of function.