• The Mathematical Education
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• v.47 no.1
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• pp.91-106
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• 2008

Interviews with 24 pupils in grade 1-2 were used to investigate awareness of the relation between situation and computation in simple quotitive and partitive division problems as informally experienced. Then it was suggested how to connect children's informal knowledge and formal knowledge of division. Most subjects counted cubes or made drawing, and related these methods to the situation described in the problems. In result, quotitive division was experienced as a dealing situation, where the number of items represented by the divisor was repeatedly taken from the whole number. And estimate-adjust was the most frequently displayed way of experiencing partitive division. Therefore, partitive division with its two measurement variables can be related to a measurement model. And children should be taught column algorithms for division with estimated-adjust which pupils used for partitive division problems.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.4
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• pp.521-539
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• 2016

The structures of partitive and quotitive division of fractions are dealt with differently, and this led to using partitive division context for helping develop invert-multiply algorithm and quotitive division for common denominator algorithm. This approach is unlikely to provide children with an opportunity to develop an understanding of common structure involved in solving different types of division. In this study, I propose two approaches, measurement approach and isomorphism approach, to develop a unifying understanding of fraction division. From each of two approaches of solving quotitive division based on proportional reasoning, I discuss an idea of constructing a measure space, unit of which is a quantity of divisor, and another idea of constructing an isomorphic relationship between the measure spaces of dividend and divisor. These ideas support invert-multiply algorithm for quotitive as well as partitive division and bring proportional reasoning into the context of fraction division. I also discuss some curriculum issues regarding fraction division and proportion in order to promote the proposed unifying understanding of partitive and quotitive division of fractions.

• School Mathematics
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• v.12 no.4
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• pp.585-604
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• 2010

This study aims to investigate understanding of meanings of division, quotitive division and partitive division, by the third graders and preservice elementary teachers. To do this, we analysed and compared mathematics textbooks according to 9 mathematics curricula, gathered information about their understanding by questionnaire method targeting 5 third graders and 36 preservice elementary teachers, and analysed their responses in relation to recognition of division-based situations, solution using visual representations, and awareness of quotitive division and partitive division. In Korea, meanings of division have been taught in grade 2 or 3 in various ways according to curricula. In particular, the mathematics textbook of present curriculum shows a couple of radical changes in relation to introduction of division. We raised the necessity of reexamination of these changes, based on our results from questionnaire analysis that show lack of understanding about two meanings of division by the preservice elementary teachers as well as the third graders. And we also induced several didactical implications for teaching meanings of division.

• Journal of Educational Research in Mathematics
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• v.17 no.2
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• pp.147-162
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• 2007

This paper reports an analysis of 19 Chinese and Korean middles school mathematics teachers' understanding of division by fractions. The study analyzes the teachers' responses to the teaching task of generating a real-world situation representing the meaning of division by fractions. The findings of this study suggests that the teachers' conceptual models of division are dominated by the partitive model of division with whole numbers as equal sharing. The dominance of partitive model of division constraints the teachers' ability to generate real-world representations of the meaning of division by fractions, such that they are able to teach only the rule-based algorithm (invert-and-multiply) for handling division by fractions.

• School Mathematics
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• v.14 no.1
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• pp.45-64
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• 2012

The purpose of the present study was to investigate middle grades (Grade 5-7) mathematics teachers' knowledge of partitive fraction division. The data were derived from a part of 40-hour professional development course on fractions, decimals, and proportions with 13 in-service teachers. In this study, I attempted to develop a model of teachers' way of knowing partitive fraction division in terms of two knowledge components: knowledge of units and partitioning operations. As a result, teachers' capacities to deal with a sharing division problem situation where the dividend and the divisor were relatively prime differed with regard to the two components. Teachers who reasoned with only two levels of units were limited in that the two-level structure they used did not show how much of one unit one person would get whereas teachers with three levels of units indicated more flexibilities in solving processes.

• The Mathematical Education
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• v.46 no.2 s.117
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• pp.155-171
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• 2007

One second grader, Junsu, was observed 4 times before and after formal multiplication lesson in Grade 2. This study describes how solution strategies in multiplication problems develop over time and investigates awareness of the relation between situation and computation in simple measurement and partitive division problems as informally experienced. It was found that Junsu used additive calculation for small-number multiplication problems but could not solve large-number multiplication problems and that he did not have concept of mathematical terms at first interview stage. After formal teaching, Junsu learned a variety of multiplication solution strategies and transferred from additive calculation to multiplicative calculation. The cognitive processing load of each strategy was gradually reduced. Junsu experienced measurement division as a dealing strategy and partitive division as a estimate-adjust strategy dealing more than one object in the first round.

• Journal of Elementary Mathematics Education in Korea
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• v.17 no.3
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• pp.395-411
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• 2013

There are two concepts of division: measurement division and partitive or fair-sharing division. Students are expected to understand comprehensively division algorithm in both contexts. Contents of textbooks and teachers' guidebooks should be suitable for helping students develop comprehensive understanding of algorithm for whole-number division in both contexts. The results of the analysis of textbooks and teachers' guidebooks shows that they fail to connect two division contexts with division algorithm comprehensively. Their expedient and improper use of two division contexts would keep students from developing comprehensive understanding of algorithm for whole-number division. Based on the results of analysis, some ways of improving textbooks and teachers' guidebooks are suggested.

• School Mathematics
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• v.9 no.1
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• pp.13-28
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• 2007

Division of fractions can be categorized as measurement division, partitive or sharing division, the inverse of multiplication, and the inverse of Cartesian product. Division algorithm for fractions has been interpreted with manipulative aids or models mainly in the contexts of measurement division and partitive division. On the contrary, there are few interpretations for the context of the inverse of a Cartesian product. In this paper the significance and the limits of existing interpretations of division of fractions in the context of the inverse of a Cartesian product were discussed. And some new easier interpretations of division algorithm in the context of a Cartesian product are developed. The problem to determine the length of a rectangle where the area and the width of it are known can be solved by various approaches: making the width of a rectangle be equal to one, making the width of a rectangle be equal to some natural number, making the area of a rectangle be equal to 1. These approaches may help students to understand the meaning of division of fractions and the meaning of the inverse of the divisor. These approaches make the inverse of a Cartesian product have many merits as an introductory context of division algorithm for fractions.

• School Mathematics
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• v.11 no.4
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• pp.685-706
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• 2009

This dissertation is aimed to investigate the reason why a contextualization is needed to help the meaningful teaching-learning concerning multiplications and divisions of fractions, the way to make the contextualization possible, and the methods which enable us to use it effectively. For this reason, this study intends to examine the differences of situations multiplying or dividing of fractions comparing to that of natural numbers, to recognize the changes in units by contextualization of multiplication of fractions, the context is set which helps to understand the role of operator that is a multiplier. As for the contextualization of division of fractions, the measurement division would have the left quantity if the quotient is discrete quantity, while the quotient of the measurement division should be presented as fractions if it is continuous quantity. The context of partitive division is connected with partitive division of natural number and 3 effective learning steps of formalization from division of natural number to division of fraction are presented. This research is expected to help teachers and students to acquire meaningful algorithm in the process of teaching and learning.

• The Mathematical Education
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• v.52 no.2
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• pp.217-230
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• 2013

This study attempts to propose the construction of textbook contents of fraction division and to suggest a method to strengthen the connection among problem context, manipulation activities and symbols by proposing an algorithm of dividing fractions based on problem contexts. As showing the suitable algorithm to problem context, it is able to understand meaningfully that the algorithm of fractions division is that of multiplication of a reciprocal. It also shows how to deal with remainder in the division of fractions. The results of this study are expected to make a meaningful contribution to textbook development for primary students.