• Journal of Educational Research in Mathematics
• /
• v.20 no.3
• /
• pp.305-322
• /
• 2010

The epistemological obstacles in the area learning of plane figure can be categorized into two types that is closely related to an attribute of measurement and is strongly connected with unit square. First, reasons for the obstacle related to an attribute of measurement are that 'area' is in conflict. with 'length' and the definition of 'plane figure' is not accordance with that of 'measurement'. Second, the causes of epistemological obstacles related to unit square are that unit square is not a basic unit to students and students have little understanding of the conception of the two dimensions. Thus, To overcome the obstacle related to an attribute of measurement, students must be able to distinguish between 'area' and 'length' through a variety of measurement activities. And, the definition of area needs to be redefined with the conception of measurement. Also, the textbook should make it possible to help students to induce the formula with the conception of 'array' and facilitate the application of formula in an integrated way. Meanwhile, To overcome obstacles related to unit square, authentic subject matter of real life and the various shapes of area need to be introduced in order for students to practice sufficient activities of each measure stage. Furthermore, teachers should seek for the pedagogical ways such as concrete manipulable activities to help them to grasp the continuous feature of the conception of area. Finally, it must be study on epistemological obstacles for good understanding. As present the cause and the teaching implication of epistemological obstacles through the research of epistemological obstacles, it must be solved.

• Journal of Elementary Mathematics Education in Korea
• /
• v.13 no.1
• /
• pp.115-140
• /
• 2009

Freudenthal has advocated the mathematisation theory. Mathematisation is an activity which endow the reality with order, through organizing phenomena. According to mathematisation theory, the departure of children's learning of mathematics is not ready-made formal mathematics, but reality which contains mathematical germination. In the first place, children mathematise reality through informal method, secondly this resulting reality is mathematised by new tool. Through survey, it turns out that area unit of Korea's seventh elementary mathematics textbook is not correspond to mathematisation theory. In that textbook, the area formular is hastily presented without sufficient real context, and the relational understanding of area concept is overwhelmed by the practice of the area formular. In this thesis, first of all, I will reconstruct area unit of seventh elementary textbook according to Freudenthal's mathematisation theory. Next, I will perform teaching experiment which is ruled by new lesson design. Lastly, I analysed the effects of teaching experiment. Through this study, I obtained the following results and suggestions. First, the mathematisation was effective on the understanding of area concept. Secondly, in both experimental and comparative class, rich-insight children more successfully achieved than poor-insight ones in the task which asked testee comparison of area from a view of number of unit square. This result show the importance of insight in mathematics education. Thirdly, in the task which asked testee computing area of figures given on lattice, experimental class handled more diverse informal strategy than comparative class. Fourthly, both experimental and comparative class showed low achievement in the task which asked testee computing area of figures by the use of Cavalieri's principle. Fifthly, Experiment class successfully achieved in the area computing task which resulting value was fraction or decimal fraction. Presently, Korea's seventh elementary mathematics textbook is excluding the area computing task which resulting value is fraction or decimal fraction. By the aid of this research, I suggest that we might progressively consider the introduction that case. Sixthly, both experimental and comparative class easily understood the relation between area and perimeter of plane figures. This result show that area and perimeter concept are integratively lessoned.

• Communications of Mathematical Education
• /
• v.19 no.3 s.23
• /
• pp.517-526
• /
• 2005

본 연구에서는 사면체의 부피를 구하는 두 가지 공식을 다룰 것이며, 이들은 외형적으로 또는 계산 방법상으로 삼각형의 넓이를 구하는 헤론의 공식과 유사하다. 이들 중에서 하나는 사면체의 모서리와 평면각들을 이용하여 사면체의 부피를 표현하며, 다른 하나는 사면체의 모서리들만 이용하여 부피를 표현한 것으로 2002년에 미해결 탐구 문제로 제시된 바 있다. 본 연구에서는 헤론 공식과 이들 두 공식의 유사점에 대해 논의하며, 모서리들만을 이용하여 부피를 구하는 공식에 대한 새로운 기초적인 증명 방법을 제시할 것이다.

• The Mathematical Education
• /
• v.45 no.3 s.114
• /
• pp.367-373
• /
• 2006

This study suggests that it is necessary to prove that the values of three areas of a triangle, which are obtained by the multiplication of the respective base and its corresponding height, are the same. It also seeks to deeply understand the meaning of Area formula of triangles by exploring some questions raised in the analysis of the proof. Area formula of triangles expresses the invariance of congruence and additivity on one hand, and the uniqueness of parallel line, one of the characteristics of Euclidean geometry, on the other. This discussion can be applied to introducing and developing exploratory learning on area in that it revisits the ordinary thinking on area.

• East Asian mathematical journal
• /
• v.31 no.2
• /
• pp.167-188
• /
• 2015

Formula for the area of a trapezoid is an educational material that can handle algebraic and geometric perspectives simultaneously. In this note, we will make up the expression equivalent algebraically to the formula for the area of a trapezoid, and deal with the conversion of a geometric point of view, in algebraic terms of translating and interpreting the expression geometrically. As a result, the geometric conversion model, the first algebraic model, the second algebraic model are obtained. Therefore, this problem is a good material to understand the advantages and disadvantages of the algebraic and geometric perspectives and to improve the mathematical insight through complementary activity. In addition, these activities can be used as material for enrichment and gifted education, because it helps cultivate a rich perspective on diverse and creative thinking and mathematical concepts.

• School Mathematics
• /
• v.16 no.4
• /
• pp.763-782
• /
• 2014

The purpose of this study is to investigate mathematics content knowledge(MCK) of pre-service teachers about the area of a circle. 53 pre-service teachers were asked to perform four tasks based on the central ideas of measurement for the area of a circle. The results of this study are as follows. First, pre-service teachers had some difficulty in describing the meaning of the area of a circle. Quite a few of them didn't recognize the necessity of counting the number of area units. Secondly, pre-service teachers had insufficient content knowledge about the central ideas of measurement for the area of a circle such as partitioning, unit iteration, rearranging, structuring an array and approximation. Lastly, few pre-service teachers understood the concept of actual infinity. Most students regarded the rectangle as the figure having the approximation error instead of the limitation from rearranging the parts of a circle.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.04a
• /
• pp.397-399
• /
• 2000

본 논문에서는 CDMA셀룰라 시스템에서 핸드오프율을 알기 위한 식을 유도하였다. 셀의 넓이를 육각형으로 모델링하고 셀을 삼각형으로 세분화함으로써, 핸드오프 영역을 간단히 공식화 하였고, 이 영역을 이용하여 한 셀 내에 발생하는 핸드오프 확률과 핸드오프 호수를 구하였다.

• Journal of Elementary Mathematics Education in Korea
• /
• v.9 no.2
• /
• pp.161-180
• /
• 2005

The purpose of this study is to delve into how elementary mathematics textbooks deal with the areas of triangles and quadrilaterals from a viewpoint of the Didactic Transposition Theory. The following conclusion was derived about the teaching of the area concept: The area concept started to be taught perfectly in the 7th curricular textbook, and the focus of area teaching was placed on the area concept, since learners were gradually given opportunities to compare and measure areas. As to the area formulae of triangles and quadrilaterals, the following conclusions were made: First, the 1st curricular, the 2nd curricular and the 3rd curricular textbooks placed emphasis on transposition by textbooks, and the 4th curricular, the 5th curricular and the 6th curricular textbooks accentuated transposition by teachers. The 7th curricular textbooks put stress on knowledge construction by learners; Second, the focus of teaching shifted from a measurement of area to inducing learners to make area formula. Namely, the utilization of area formula itself was accentuated, while algorithm was emphasized in the past; Third, the way to encourage learners to produce area formula changed according to the curricula and in light of learners' level, but a wide range of teaching devices related to the area formulae were removed, which resulted in offering less learning chances to students; Fourth, what to teach about the areas of triangles and quadrilaterals was gradually polished up, and the 7th curricular textbooks removed one of the overlapped area formula of triangle.

• Journal of Educational Research in Mathematics
• /
• v.27 no.2
• /
• pp.207-225
• /
• 2017

With a significant role of textbooks in shaping students' opportunities to learn, textbook analysis is essential to reveal these opportunities to learn the concept of area and volume. This research aims to show how the Korean textbooks pace students' learning of area and volume across grades by scrutinizing the textbooks with students' developmental sequences, called learning trajectories. Tasks about area and volume in all Korean elementary textbooks (grade 1 to 6) are coded with the specific developmental stages suggested in learning trajectories. As a result, we find considerable misalignment between the textbooks and the learning trajectories. The textbooks provide opportunities to experience developmental progressions of area and volume later than ages suggested in the learning trajectories. In addition, learning opportunities are significantly concentrated in grade 5 for area and grade 6 for volume with heavy emphases on applying formulas of area or volume. The findings from this research provides important implications concerning design of textbooks as well as improving students' opportunities in the mathematics classrooms.

• School Mathematics
• /
• v.8 no.3
• /
• pp.327-339
• /
• 2006

In this study, a teaching units for teaching and learning of secondary preservice teachers' mathematising is designed, focusing on reinvention of Bretschneider's formula. preservice teachers can obtain the following through this teaching units. First, preservice teachers can experience mathematising which invent a noumenon which organize a phenomenon, They can make an experience to invent Bretscheider's formula as if they invent mathematics really. Second, preservice teachers can understand one of the mechanisms of mathematics knowledge invention. As they reinvent Brahmagupta's formula and Bretschneider's formula, they understand a mechanism that new knowledge is invented Iron already known knowledge by analogy. Third, preservice teachers can understand connection between school mathematics and academic mathematics. They can understand how the school mathematics can connect academic mathematics, through the relation between the school mathematics like formulas for calculating areas of rectangle, square, rhombus, parallelogram, trapezoid and Heron's formula, and academic mathematics like Brahmagupta's formula and Bretschneider's formula.