• The Mathematical Education
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• v.59 no.3
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• pp.255-269
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• 2020

In this study, how to instruct the computational estimation of addition and subtraction was considered from the perspective of a 'intended-written-implemented' multi-dimensional curriculum. To this end, the 2015 revised elementary school mathematics curriculum as a intended curriculum and the 2015 revised first~sixth grade textbook as a written curriculum were analyzed with respect to how to instruct the computational estimation of addition and subtraction. As an implemented curriculum, a research study was conducted in relation to the method of instructing teachers about the computational estimation of addition and subtraction. As a result, first, it is necessary to discuss how to develop the ability to estimate and set it as a teaching goal and achievement standard in a separate curriculum to instruct it with learning content. Second, it is necessary to provide an opportunity to learn about various estimation methods by presenting specific activities so that students can learn the estimation itself in a separate operation method. Third, in order to improve the computational estimating ability of addition and subtraction, contents related to the computational estimation need to be included in the achievement criteria, and discussions on the expansion of the areas, and the diversification of the instructing time will be needed.

• Journal of the Korean School Mathematics Society
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• v.16 no.4
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• pp.675-694
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• 2013

The purposes of this study were to investigate teachers' perceptions on process-focused mathematics assessment using manipulatives and technological devices and to propose the direction of the process-focused mathematics assessment. This study was conducted by the survey method with a total of 332 elementary and secondary school mathematics teachers working in Seoul or Gyeonggi areas who had experienced in using manipulatives and technological devices. According to the results, the use of manipulatives and technological devices in the process-focused mathematics assessment will facilitate the use of various alternative assessment methods such as research-report, project, and discussion for the process-focused mathematics assessment. Those alternative assessment methods enable teachers to diagnose students' learning in more accurate and holistic views and contribute to improving teachers' teaching practices focused on the mathematical process.

• Communications of Mathematical Education
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• v.29 no.1
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• pp.91-110
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• 2015

The purpose of this study is to investigate the understanding of pi of elementary gifted students and explore improvement direction of teaching pi. The results of this study are as follows. First, students understood insufficiently the property of approximation, constancy and infinity of pi from the fixation on 'pi = 3.14'. They mixed pi up with the approximation of pi as well. Second, they had a inclination to understand pi as algebraic formula, circumference by diameter. Third, few students understood the property of constancy and infinity of pi deeply. Lastly, the discussion activity provided the chance of finding the idea of the property of approximation of pi. In conclusion, we proposed several methods which improve the teaching of pi at elementary school.

• Communications of Mathematical Education
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• v.22 no.1
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• pp.41-52
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• 2008

In this paper, some factors such as the perspective of children, instructional materials(especially activities in textbooks for elementary school mathematics), and teacher's questioning styles are discussed as ones influenced on students' immersion in leaner-centered instruction. This discussion is based on the author's two implementations of the kind of two instructions. About the first theme, constructivists assert that even children who are in elementary school can have reflective abstracting ability. Teachers' asking questions with the belief differ from ones with traditional perspective of children, which is relevant the third factor. They value and respect learners' thinking outcomes, even though they are not sometimes wrong and have errors. Also, they have them opportunities to think different from others and to ask how they get their answers. To do these, they frequently ask open-ended questions, not closed. All of them is possible through the activities provided in textbooks. Some characteristics which can prompt such teacher's questions using activities in elementary mathematics textbooks are discussed.

• Communications of Mathematical Education
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• v.32 no.1
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• pp.1-22
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• 2018

The purpose of the study was to examine the effects of mentoring experience in STEAM classes on pre-service mathematics teachers' teaching competency for STEAM education. The study was conducted with 23 pre-service mathematics teachers who participated in the mentoring program affiliated with free learning semester system during one semester. To investigate the changes of pre-service mathematics teachers' teaching competencies for STEAM education and the effects of the mentoring program, pre, post questionnaires, lesson journals, and whole group discussion data were collected. According to the results, pre-service mathematics teachers' competencies for 'knowledge of STEAM education', 'subject matter knowledge', 'teaching and learning methods', and 'learning environments and circumstances' categories were improved significantly after the mentoring program. Especially, some results indicated that pre-service mathematics teachers' teaching experiences in real STEAM classrooms were very helpful for the development of understandings of STEAM education and construction of practical knowledge.

• Communications of Mathematical Education
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• v.20 no.3 s.27
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• pp.443-467
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• 2006

The purpose of this study was to study the 2nd grade elementary students' common thinking and differences of additive and multiplicative thinking. For meaningful discussion of the above, we have established the following research questions. 1. What are the properties of the multiplicative thinking of 2nd grade elementary students? - What are the common properties of the multiplicative thinking of 2nd grade elementary students? - What are the properties of the various multiplicative thinking levels? 2. How is multiplicative thinking presented in Korean math textbooks? The conclusions of this study were followings: First, the 2nd grade elementary students in the multiplicative thinking learnt used by translating multiplication into specific situations. And they often used different models of multiplication. Second, additive thinking developed into the multiplicative thinking. After being helped by their teachers, students who thought additively were then able to think multiplicatively. Whereas after being helped by their teachers, students who were already competent at multiplicative thinking gained a deeper understanding. Third, they learned the commutative property of multiplication after their understanding of the 'repeated addition approach' and the multiplicative approach was sufficiently reinforced. Last, students should be taught using different models based on the repeated addition approach.

• Proceedings of the Korea Society for Simulation Conference
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• 1994.10a
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• pp.1-2
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• 1994

With the prevalence of computers in modern organizations, simulation is receiving more atention as an effectvie decision -making tool. Simualtion is a computer-based numerical technique which uses mathmatical and logical models to approximate the behaviror of a real-world system. However, iptimization of synamic stochastic systems often defy analytical and algorithmic soluions. Although a simulation approach is often free fo the liminting assumption s of mathematical modeling, cost and time consiceration s make simulation the henayst's last resort. Therefore, whenever possible, analytical and algorithmica solutions are favored over simulation. This paper discussed the issues and procedrues for using simulation as a tool for optimization of stochastic complex systems that are dmodeled by computer simulation . Its emphasis is mostly on issues that are speicific to simulation optimization instead of consentrating on the general optimizationand mathematical programming techniques . A simulation optimization problem is an optimization problem where the objective function. constraints, or both are response that can only be evauated by computer simulation. As such, these functions are only implicit functions of decision parameters of the system, and often stochastic in nature as well. Most of optimization techniqes can be classified as single or multiple-resoneses techniques . The optimization of single response functins has been researched extensively and consists of many techniques. In the single response category, these strategies are gradient based search techniques, stochastic approximate techniques, response surface techniques, and heuristic search techniques. In the multiple response categroy, there are basically five distinct strategies for treating the responses and finding the optimum solution. These strategies are graphica techniqes, direct search techniques, constrained optimization techniques, unconstrained optimization techniques, and goal programming techniques. The choice of theprocedreu to employ in simulation optimization depends on the analyst and the problem to be solved. For many practival and industrial optimization problems where some or all of the system components are stochastic, the objective functions cannot be represented analytically. Therefore, modeling by computersimulation is one of the most effective means of studying such complex systems. In this paper, after discussion of simulation optmization techniques, the applications of above techniques will be presented in the modeling process of many flexible manufacturing systems.

• Communications of Mathematical Education
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• v.24 no.3
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• pp.731-744
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• 2010

Nowadays in school mathematics, the skill and method for solving problems are often emphasized in preference to the theoretical principles of mathematics. Students pay attention to how to make an equation mechanically before even understanding the meaning of the given problem. Furthermore they do not get to really know about the principle or theorem that were used to solve the problem, or the meaning of the answer that they have obtained. In contemporary textbooks the conic section such as circle, ellipse, parabola and hyperbola are introduced as the cross section of a cone. But they do not mention how conic section are connected with the quadratic equation or how these curves are related mutually. Students learn the quadratic equations of the conic sections introduced geometrically and are used to manipulating it algebraically through finding a focal point, vertex, and directrix of the cross section of a cone. But they are not familiar with relating these equations with the cross section of a cone. In this paper, we try to understand the quadratic curves better through the analysis of the discussion made in the process of the discovery and eventual development of the conic section and then seek for way to improve the teaching and learning methods of quadratic curves.

• Communications of Mathematical Education
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• v.23 no.3
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• pp.625-642
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• 2009

In the school mathematics the concept of tangent is introduced in several steps in suitable contexts. Students are required to reflect and revise their concepts of tangent in order to apply the improved concept to wider range of contexts. In this paper we consider the tangent as the optimal linear approximation to a curve at a given point and make three discussions on pedagogical aspects of it. First, it provides a method of finding roots of real numbers which can be used as an application of tangent. This may help students improve their affective variables such as interest, attitude, motivation about the learning of tangent. Second, this concept reflects the modern point of view of tangent, the linear approximation of nonlinear problems. Third, it gives precise meaning of two tangent lines appearing two sides of a cusp point of a curve.

• Communications of Mathematical Education
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• v.33 no.3
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• pp.255-273
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• 2019

In order to help students to understand the essence of prime concepts, this study looked at the history of prime concept development and analyzed how to introduce the concept of textbooks. In ancient Greece, primes were multiplicative atoms. At that time, the unit was not a number, but the development of decimal representations led to the integration of the unit into the number, which raised the issue of primality of 1. Based on the uniqueness of factorization into prime factor, 1 was excluded from the prime, and after that, the concept of prime of the atomic context and the irreducible concept of the divisor context are established. The history of the development of prime concepts clearly reveals that the fact that prime is the multiplicative atom is the essence of the concept. As a result of analyzing the textbooks, the textbook has problems of not introducing the concept essence by introducing the concept of prime into a shaped perspectives or using game, and the problem that the transition to analytic concept definition is radical after the introduction of the concept. Based on the results of the analysis, we have provided several pedagogical implications for helping to focus on a conceptual aspect of prime number.