• Journal of Elementary Mathematics Education in Korea
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• v.20 no.3
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• pp.457-477
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• 2016

The purpose of this study is to analyze and diagnose the type of errors indicated by the students in the process of calculation of the fractional multiplication and division, and to propose teaching methods, to effectively correct errors. The results obtained through this study are as follows. First, based on the results of the preliminary examination, 6 types of errors of the fractional multiplication and division has been organized. In particular, the most frequent types of errors are algorithm errors. Therefore, a teacher should explain the meaning and concept of fractional multiplication and division. Second, 4 prescription methods are proposed for understanding fractional multiplication and division. Third, according to the results of this study, it was effective to diagnose underachievers' error types and give corrective lesson according to the cause of the error types. Throughout the study, it's concluded that it is necessary to analyze and diagnose the error types of fractional multiplication and division, and then a teacher can correct error types by 4 proposed prescription methods. Also, 5 students showed interest while learning, and participated actively.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.3
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• pp.479-498
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• 2016

Time is important in children's lives since their preschool years. However, previous studies indicate that many children struggle with the acquisition of time concepts. Also teachers do not know how to help them. This study aims to investigate elementary school students' understanding about time and induce its educational implications. To do this, about 130 children from first to fifth grades were tested for their ability to recognize(read and record) the analogue and digital times and to solve elapsed-time problems. The results showed that even first graders were able to read and record the minute times on digital clocks. And second graders were able to read and record the minute times on analogue clocks. Therefore, the ability to recognize analogue times was mastered by second grade. In case of the elapsed-time problems, there was statistically significant difference according to school years or types of problems. Students were successful in solving simple problems. However, the problems that include regrouping hour and minute remained difficult even for the older children. Based on these results, we made a few suggestions for teaching practice about time.

• Journal of Educational Research in Mathematics
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• v.21 no.4
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• pp.399-422
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• 2011

There has been an agreement on the necessity for each citizen is to be educated, so called, to develop quantitative literacy or statistical literacy, dealing with real world data. For this reason, it is highly demanded to improve traditional statistics education. In particular, critical thought and statistical communication competency cultivation is becoming more crucial in statistics classes. In line with this reform movement in statistics education, we developed tasks facilitating statistical debate among students through inducing cognitive conflict. The tasks employed for this study resulted in playing crucial role to activate statistical debate. Including aforementioned feature about the tasks for this study, we obtained several positive results such as promoting critical thought and conceptual extension by designed teaching experiment focusing on statistical debate.

• School Mathematics
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• v.11 no.3
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• pp.513-526
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• 2009

The purpose of this paper intuitively shows the exact and logical explanation of Independent Event and Dependent Event. In actual classrooms, teachers have difficulty in describing the connection between those events and real life. Some teachers have wrong perceptions on the definition of those events. For example, they may not realize exactly what P(B A)=P(B) means and may not explain intuitively the original meaning of why it is independent event. Also they believe that Independent Event and Dependent Event do not always match with real life. This paper, therefore, tries to prove intuitively the exact meanings of those events in the Verbal Form with some examples and it proves that those events exactly match with real life. It is expected that this paper will greatly contribute to the improvement of probability education.

• School Mathematics
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• v.18 no.4
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• pp.881-901
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• 2016

This study is about investigating students' recognition and expression on relationship of 'time, distance, speed' via teaching experiment. In this process, students showed not only a change in perception of the relationship of 'time, distance, speed' but also recognizing the average speed as a viewpoint of the slope of the line connecting the end points of the interval in the distance function as well as another way of perceiving average speed of a height of a rectangle. In this process, the study shows the scene of expanding the relation of 'distance = time ${\times}$ speed' to 'distance = time ${\times}$ average speed', and also the student who makes the continuous reasoning shows the possibility of constructing a new function that can explain the change of the primitive function by allocating the average rate of change to the interval. Although this study was conducted with a limited number of students, this study suggests some implications through the observation of relationship of 'time, distance, speed' the students'. We hope that these results will be the starting point for various studies for constructing the integral learning model in the future.

• School Mathematics
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• v.18 no.4
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• pp.793-818
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• 2016

The purpose of this study is to explore in detail $5^{th}$ grade students' understanding on the big ideas related to addition of fraction with different denominators: fixed whole unit, necessity of common measure, and recursive partitioning connected to algorithms. We conducted teaching experiments on 15 fifth grade students who had learned about addition of fractions with different denominators using the current textbook. Most students approached to the big ideas related to addition of fractions in a procedural way. However, some students were able to conceptually understand the interpretations and algorithms of fraction addition by quantitatively thinking about the context and focusing on the structures of units. Building on these results, this study is expected to suggest specific implications on instruction methods for addition of fractions with different denominators.

• School Mathematics
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• v.4 no.2
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• pp.161-192
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• 2002

This paper investigated the teaching and teaming of contents-related graphing in Korean secondary textbooks and suggested the improved methods of graph instruction through this analysis. reification-the case of function, In Harel, G., Dubinsky(Eds.), The Concept of Function : Aspects of Epistemology and Pedagogy Textbooks are analyzed from the viewpoint of the proportion of graphing contents, their sequencing, the proportion of each domain in graphing activities (interpretation vs. construction, quantitative vs. qualitative aspect, local vs. global aspect) and tasks (prediction, translation, scaling), and the difference in the graphing contents between the sixth and the seventh curriculum. This analysis demonstrates that graphing contents are increasing in textbooks, therefore the high school textbooks appear in almost every content area. The graphing activities concentrate on the construction, the quantitative aspects, and the local aspects, and are gradually focusing on the interpretation and global aspects of high school textbooks. Furthermore, most of graphing tasks favor translation. In contrast, the current seventh curriculum includes a balance of interpretation and construction activities and has more global aspects than the sixth curriculum based textbooks; however, the qualitative approach still rarely appears. For the graphing tasks, translation is still prevalent, but the importances of prediction tasks based on graph have increased in comparison with the sixth curriculum textbooks. Further, the seventh curriculum based textbooks are designed to stimulate more dynamic graphing instruction by introducing new tools such as graphing calculators and computer software. We suggest that the qualitative and global aspects should be emphasized in early graph instruction, a variety of graph activities in realistic contexts should be performed, and educational technology such as graphing calculator and computer can be efficient to implement these ideas.

• Journal of Educational Research in Mathematics
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• v.22 no.1
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• pp.23-38
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• 2012

The purpose of this paper is to describe the true meaning of smooth curve and to let people understand the smooth curve by way of velocity. It is true that it is not easy for us to perceive smooth curve because when there are no cups in the curve and the shape of the curve looks smooth, we often perceive it is smooth curve. However, even when the shape of curve looks smooth, it happens that it is not smooth curve. When the particle moves on the curve, depending on the velocity, it can be smooth curve or not. That is, even though the shape looks smooth, when the velocity is discontinuous or it is 0, it is not smooth curve. Therefore, this paper shows that it is important to understand and to teach smooth curve by way of velocity. In other words, when parameter of path for the smooth curve is taught in the calculus of high school, it needs to be understood by way of velocity. Finally, this paper tries to suggest that we need to shift our paradigm in teaching of smooth curve from fixed curve to dynamic curve.

• School Mathematics
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• v.13 no.1
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• pp.107-125
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• 2011

In this paper, we investigated how the GSP environments impact students' conjecturing of geometric properties. And we wanted to draw some implication in teaching and learning geometry in dynamic geometric environments. As results, we conclude that when students were given the problem situations which almost has no condition, they were not successful, and rather when the problem situations had appropriate conditions students were able to generate many conditions which were not given in the original problem situations, and consequently they were more successful in conjecturing geometric properties. And the geometric properties conjectured in GSP environments are more complex and difficult to prove than those in paper and pencil environments. Also the function of moving screen with 'Alt' key is frequently used in conjecturing geometric properties with functions of measurement and calculation of GSP. And students felt happier when they discovered geometric properties than when they could prove geometric properties.

• School Mathematics
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• v.10 no.3
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• pp.319-337
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• 2008

Intuitions in independence formed by common language help and also hinder the establishment of new conceptual system about independence as a mathematical term. Intuitions which entail such conflicts can be a driving force in explaining independence but at the same time, it is the impedimental factor causing a misconception. The goal of this paper is to help students use the intuitions properly by distinguishing helpful intuitions and impedimental intuitions. This paper suggests that we need to reveal in teaching the misconception resulting not from mathematic but from linguistic interpretation of independence. This paper points out the need for the clear distinction of independence of trials and independence of events and gives an counterexample of the case that sampling with and without replacement shouldn't be specified as a representative example of independence and dependence of events. The analysis of intuition in this parer is based on intuitions classified by Fischbein and this paper analyzed institutions applied to the concept of independence corresponding intuitions classified by Fischbein.