• Journal of Elementary Mathematics Education in Korea
• /
• v.22 no.4
• /
• pp.331-368
• /
• 2018

This study is derived from a student who can add without knowing the addition principle. To understand where the student's response come from, we came to analyse the curriculum contents of natural numbers, decimals and fractions addition principle. At the same time, we surveyed two different school of forty six sixth grade participants with questionnaires to determine whether it is a problem of the student or an universal one. As a result, we found that there is a room for improvement in the addition and connections of addition. We propose appropriate instructional method regarding connections of addition and addition principle of natural numbers, decimals and fractions. The conclude there is a close relation and differences among the principles of natural numbers, decimals and fractions in the proposed instructional method. Therefore, we need to consider and instruct the differences of the number expansion.

• School Mathematics
• /
• v.19 no.1
• /
• pp.137-151
• /
• 2017

This study aims to investigate the possibility of elementary students' generalization from three-digit numbers to multi-digit numbers in principles for addition and subtraction. One of main changes was the reduction of range of numbers for addition and subtraction from four-digit to three-digit. It was hypothesized that the students could generalize the principles of addition and subtraction after learning the three-digit addition and subtraction. To achieve the purpose of this study, we selected two groups as a sampling. One is called 'group 2015' who learned four-digit addition and subtraction and the other is called 'group 2016' who learned addition and subtraction only to three-digit. Because of the particularity of these subjects, this study covered two years 2015~2016. We applied our addition and subtraction test which contains ten three-digit or four-digit addition and subtraction items, respectively. We collected their results of the test and analyzed their differences using t-test. The results showed statistically meaningful difference between the mean score of the two groups only for four-digit subtraction. Based on the result, we discussed and made some didactical suggestions for teaching multi-digit addition and subtraction.

• Journal of Elementary Mathematics Education in Korea
• /
• v.3 no.1
• /
• pp.21-39
• /
• 1999

In this paper, we first exam the relation between Piaget's theory of cognitive development and cognitive constructivism. With it's outcome We find three principles of constructivist teaching-learning methods for primary mathematics These are as follows 1) active learning based on self-regulatory process 2) empirical learning by self initiated activities 3) individual learning derived from present cognitive structure and fits of new experiences. Finally we introduce several examples for classroom practice applied the above principles in primary mathematics.

• Journal for History of Mathematics
• /
• v.9 no.1
• /
• pp.12-31
• /
• 1996

주판은 지난 수천년동안 인류가 애용했던 산판(abacus)의 일종으로서, 휴대용 계산기(Calculator)가 보편화되기 전까지 덧셈이나 곱셈 등의의 사칙연산을 수행하는 데에 사용된 대표적인 산술도구이다. 한편, 자동화를 위한 단순한 계산기계로부터 발전되어 온 컴퓨터는 오늘날 디지털 시대를 주도하면서 불과 수십년만에 우리의 삶과 생각을 완전히 새로운 모습으로 바꾸어 놓은 또 하나의 산술도구인 것이다. 본 논문에서는 주판에 적용된 여러 가지 산술원리들을 역사적으로 살펴본뒤, 산술의 발전과 컴퓨터 사이에 어떠한 상관관계가 있는 지를 살펴보고자 한다. 이를 위하여, 새로운 산술원리를 컴퓨터에 도입하게 된 동기와 파급효과를 주판의 경우와 대비하여 설명하고, 현재 진행중인 컴퓨터 산술(computer arithmetic)분야의 연구동향을 토대로 미래의 컴퓨터를 전망한다.

• Journal of Elementary Mathematics Education in Korea
• /
• v.4 no.1
• /
• pp.21-37
• /
• 2000

Although methods about teaching basic principles and skills of addition and subtraction is long traditional, view points of interpreting those algorithms and ways of introducing those calculating skills are various according to textbooks at each historical stage of elementary mathematics curriculum development in Korea. The 1st and 2nd stage shows didactic transpositions less systemic. In the 3rd and 4th stage, didactic devices, which were influenced by the new math, for help of understanding the principles of addition and subtraction muchly depends on mathematical and logical mechanism rather than psychological and intellectual structure of students who learn those algorithms. Relatively compromising and stable forms appear in the 5th and 6th stages. Didactic transpositions in the 7th stage focus on the formation of mathematical concepts by exploration activities rather than on the presentation of mathematical contents by text. Anyone who wishes to design an elementary mathematics textbooks based upon the constructive view should consider the suggestions derived from such transition.

• Journal for History of Mathematics
• /
• v.23 no.3
• /
• pp.121-140
• /
• 2010

This study presents one universal mean formula of implicate quantity for speed, temperature, consistency, density, unit cost, and the national income per person in order to avoid the inconvenience of applying different formulas for each one of them. This work is done by using the principle of lever and was led to the formula of two implicate quantity, $M=\frac{x_1f_1+x_2f_2}{f_1+f_2}$, and to help the understanding of relationships in this formula. The value of ratio of fraction cannot be added but it shows that it can be calculated depending on the size of the ratio. It is intended to solve multiple additions with one formula which is the expansion of the mean formula of implicate quantity. $M=\frac{x_1f_1+x_2f_2+{\cdots}+x_nf_n}{N}$, where $f_1+f_2+{\cdots}+f_n=N$. For this reason, this mean formula will be able to help in physics as well as many other different fields in solving complication of structures.

• Journal of Elementary Mathematics Education in Korea
• /
• v.14 no.2
• /
• pp.241-262
• /
• 2010

This study was carried out to identify the cognitive obstacles while using addition and subtraction with fractions, and to analyze the sources of cognitive obstacles. For this purpose, the following research questions were established : 1. What errors do elementary students make while performing the operations with fractions, and what cognitive obstacles do they have? 2. What sources cause the cognitive obstacles to occur? The results obtained in this study were as follows : First, the student's cognitive obstacles were classified as those operating with same denominators, different denominators, and both. Some common cognitive obstacles that occurred when operating with same denominators and with different denominators were: the students would use division instead of addition and subtraction to solve their problems, when adding fractions, the students would make a natural number as their answer, the students incorporated different solving methods when working with improper fractions, as well as, making errors when reducing fractions. Cognitive obstacles in operating with same denominators were: adding the natural number to the numerator, subtracting the small number from the big number without carrying over, and making errors when doing so. Cognitive obstacles while operating with different denominators were their understanding of how to work with the denominators and numerators, and they made errors when reducing fractions to common denominators. Second, the factors that affected these cognitive obstacles were classified as epistemological factors, psychological factors, and didactical factors. The epistemological factors that affected the cognitive obstacles when using addition and subtraction with fractions were focused on hasty generalizations, intuition, linguistic representation, portions. The psychological factors that affected the cognitive obstacles were focused on instrumental understanding, notion image, obsession with operation of natural numbers, and constraint satisfaction.

• Journal of Elementary Mathematics Education in Korea
• /
• v.13 no.2
• /
• pp.285-304
• /
• 2009

The operations of fractions are the main contents of number and operations in the elementary mathematics curriculum. They are also difficult for students to understand conceptually. Nevertheless, there has been little study on the addition and subtraction of fractions. Given this, this paper explored the connection between the national mathematics curriculum and its concomitant textbooks, the adequacy of when to teach, and the method of constructing each unit to teach addition and subtraction of fractions. This paper then analyzed elementary mathematics textbooks and workbooks by three parts aligned with the general instructional flow: 'introduction', 'activity', and, 'exercise'. First, it was analyzed with regard to the introduction part whether the word problems of textbooks might reflect on students' daily lives as intended, how different meanings of operations would be expected to be taught, and how the subsequent activities were connected with the original word problems. Second, the main analysis of activity part of the textbooks dealt with how to use concrete or iconic models to promote students' conceptual understanding of operations and how to formalize the calculation methods and principles with regard to addition and subtraction of fractions. Third, the analysis of the part of exercise in the textbooks and workbooks was conducted with regard to problem types and meanings of operations. It is expected that the issues and suggestions stemming from this analysis of current textbooks and workbooks are informative in developing new instructional materials aligned to the recently revised mathematics curriculum.

• Journal of Educational Research in Mathematics
• /
• v.19 no.2
• /
• pp.307-319
• /
• 2009

Current school mathematics introduces addition/subtraction between natural numbers, fractions, decimal fractions, and square roots, step-by-step in order. It seems that, however, school mathematics focuses too much on learning the calculation method of addition/subtraction between each stages of numbers, to lead most of students to understand the coherent principle, lying in addition/subtraction algorithm between real numbers in all. This paper raises questions on this problematic approach of current school mathematics, in learning addition/subtraction. This paper intends to clarify the fact that, if we recognize addition/subtraction between numbers from the viewpoint of 'measuring' and 'common measure', as Dewey did when he argued that the psychological origin of the concept of number was measuring, then we could find some common principles of addition/subtraction operation, beyond the superficial differences among algorithms of addition/subtraction between each stages of numbers. At the end, this paper suggests the necessity of improving the methods of learning addition/subtraction in current school mathematics.