• Journal of Educational Research in Mathematics
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• v.11 no.1
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• pp.223-238
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• 2001

Decimal fractions are the practical system of notations representing real numbers. The set of decimal fractions with the definition of comparison of decimal fractions and the identification of their double representations is essentially the field of real numbers. Therefore, we have to clarify the concept of decimal fractions. However, there are problematics that the aquisition of the concept of decimal fractions is not easy. In this paper, we attempt to eradicate the problematics relevant to the acquisition of decimal fractions discussed above and find the desirable direction of instruction of meaning for mathematical symbols: The case of decimal fractions. In J. Hiebert & decimal fractions. First of all, we clarify the essence of them - ratio, operator and linearity. And we compare and analyse the theories about decimal fractions of Resnick, Drexel, Brousseau and Hiebert and the contents of texts about decimal fractions in Korea. Finally, we suggest the efficient instruction methods which are faithful to the essence of decimal fractions and choose some methods among them to plan the classroom instruction and implement the methods in the classroom.

• Journal for History of Mathematics
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• v.20 no.2
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• pp.89-108
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• 2007

Finding the lack of meaningful approaches in teaching multiplication of decimal fractions, this paper tries to show from the standpoints of Dewey, Vergnaud and Brousseau that the cognition of ratio and proportion is essential to the understanding of multiplication of decimal fractions. Based upon such posture, this paper compares the characteristics and approaches to multiplication of decimal fractions in Korean and Japanese textbooks. Finally, this paper suggests ways to develop the concept of multiplication of decimal fractions in Korean textbooks.

• Journal of Elementary Mathematics Education in Korea
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• v.22 no.4
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• pp.475-496
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• 2018

Although the multiplication of decimal fractions is expected to be easy for students to understand because of the similarity to natural numbers multiplication in computing methods, students show many errors in the multiplication of decimal fractions. This is a result of the instruction focused more on skill mastery than conceptual understanding. This study is a basic study for effectively developing a unit of multiplication of decimal fractions. For this purpose, we analyzed the curriculums' performance standards, significance in teaching-learning and evaluation, contents and methods for teaching multiplication of decimal fractions from the 7th curriculum to the revised curriculum of 2015 and the textbooks' activities and lessons. Further, we analyzed preceding studies and introductory books to suggest effective directions for developing teaching unit. As a result of the analysis, three implications were obtained: First, a meaningful instruction for estimation is needed. Second, it is necessary to present a visual model suitable for understanding the meaning of decimal multiplication. Third, the process of formalizing an algorithms for multiplying decimal fractions needs to be diversified.

• Journal for History of Mathematics
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• v.18 no.3
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• pp.55-66
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• 2005

In our school mathmatics, the irrational numbers and the real numbers are defined and instructed on the basis of decimal fractions. In relation to this fact, we identified the essences of the real number and the irrational number defined by the decimal fractions through the historical analysis. It is revealed that the formation of real numbers means the numerical measurements of all magnitudes and the formation of irrational numbers means the numerical measurements of incommensurable magnitudes. Finally, we suggest instructional plan for the meaninful understanding of the real number concept.

• Journal of Educational Research in Mathematics
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• v.21 no.2
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• pp.121-134
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• 2011

Stevin is known as the inventor of decimal fractions, even though many mathematicians had the concept of decimal fractions and used it before Stevin. Why? To respond to such a question, we studied about its significance which 'La Disme' had in the history of mathematics. These can be summarized as its notational aspect, the manner of developing the book, the conceptual revolution and the practical purpose. And the chapter and verse of are little known when compared to its reputation. So in this paper we considered its contents in detail and discussed some didactical implications in relation to teaching and learning of decimal fractions in elementary school : importance of place values, similarity of calculation to natural numbers, using common fractions to justify, emphasis on the applications of decimal fractions, relation to measuring units, necessity of teaching number sense, using notational aspects.

• The Mathematical Education
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• v.45 no.3 s.114
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• pp.275-293
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• 2006

The purpose of this study was to analyze the connection between students' errors and prior knowledge as an attempt to design an efficient teaching method in decimal computation. A survey on decimal computations was conducted in two 6th grade elementary school classrooms. Error patterns on decimal computations were analyzed and clinical interviews were conducted with 8 students according to their error patterns. Main errors resulted from the insufficient understanding of prior knowledge such as place value, connection between decimals and fractions, meaning of operations, and computation principles of fractions. In order to help students overcome such obstacles, a teaching experiment was designed in a manner that strengthens a profound understanding of prior knowledge related to decimal computations, and connects such knowledge to actual decimal calculations. This study showed that well-designed lesson plans with base-ten blocks might decrease students' errors by helping them understand decimals and connect their prior knowledge to decimal operations.

• Journal of Elementary Mathematics Education in Korea
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• v.23 no.1
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• pp.1-17
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• 2019

In this study, prospective teachers were involved in arranging the teaching sequence of multiplication and division of fractions and decimal numbers based on their experience and knowledge of school mathematics. As a result, these activities provided an opportunity to demonstrate the prospective teachers' perception. Prospective teachers were able to learn the knowledge they needed by identifying the differences between their perceptions and curriculum. In other words, prospective teachers were able to understand the mathematical relationships inherent in the teaching sequence of multiplication and division of fractions and decimal numbers and the importance and difficulty of identifying students' prior knowledge and the effects of productive failures as teaching methods.

• Journal of Educational Research in Mathematics
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• v.27 no.3
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• pp.351-373
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• 2017

The meanings of division don't change and rather are connected from whole numbers to rational numbers. In this respect, connecting division of natural numbers, division of fractions, and division of decimal numbers could help for students to study division in meaningful ways. Against this background, the units of division of fractions and division of decimal numbers in fifth grade were redesigned in a way for students to connect meanings of division and procedures of division. The results showed that most students were able to understand the division meanings and build correct expressions. In addition, the students were able to make appropriate division situations when given only division expressions. On the other hand, some students had difficulties in understanding division situations with fractions or decimal numbers and tended to use specific procedures without applying diverse principles. This study is expected to suggest implications for how to connect division throughout mathematics in elementary school.

• 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.15 no.1
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• pp.1-18
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• 2011

The purpose of this study was to investigate the effects of estimation strategy on placing decimal point in multiplication and division of decimals. To examine the effects of improving calculation ability and reducing decimal point errors with this estimation strategy, the experimental research on operation with decimal was conducted. The operation group conducted the decimal point estimation strategy for operating decimal fractions, whereas the control group used the traditional method with the same test paper. The results obtained in this research are as follows; First, the estimation strategy with understanding a basic meaning of decimals was much more effective in calculation improvement than the algorithm study with repeated calculations. Second, the mathematical problem solving ability - including the whole procedure for solving the mathematical question - had no effects since the decimal point estimation strategy is normally performed after finishing problem solving strategy. Third, the estimation strategy showed positive effects on the calculation ability. Th Memorizing algorithm doesn't last long to the students, but the estimation strategy based on the concept and the position of decimal fraction affects continually to the students. Finally, the estimation strategy assisted the students in understanding the connection of the position of decimal points in the product with that in the multiplicand or the multiplier. Moreover, this strategy suggested to the students that there was relation between the placing decimal point of the quotient and that of the dividend.