• School Mathematics
• /
• v.9 no.1
• /
• pp.1-12
• /
• 2007

The purpose of this study is searching for the problems and alternatives on teaching for repeating decimal. To accomplish the purpose, we have analyzed the fifth, sixth, and seventh Korean national curriculums, textbooks and examinations for the eighth grade about repeating decimal. W also have analyzed textbooks from USA to find for alternatives. As the results, we found followings. First, the national curriculums blocked us verifying the relation between rational number and repeating decimal. Second, definitions of terminating decimal, infinite decimal, and repeating decimal are slightly different in every textbooks. This leads seriously confusion for students examinations. The alternative on these problems is defining the terminating decimal as following; decimal which continually obtains only zeros in the quotient. That is, we have to avoid the representation of repeating decimal repeated nines under a declared system which apply an infinite decimal continually obtaining only zeros in the quotient. Then, we do not have any problems to verify the following statement. A number is a rational number if and only if it can be represented by a repeating decimal.

• Journal of the Korean School Mathematics Society
• /
• v.10 no.2
• /
• pp.237-246
• /
• 2007

According to 7-th curriculum, irrational number should be introduced using non-repeating infinite decimals. A rational number is defined by a number determined by the ratio of some integer p to some non-zero integer q in 7-th grade. In 8-th grade, A number is rational number if and only if it can be expressed as finite decimal or repeating decimal. A irrational number is defined by non-repeating infinite decimal in 9-th grade. There are misconceptions about a non-repeating infinite decimal. Although 1.4532954$\cdots$ is neither a rational number nor a irrational number, many high school students determine 1.4532954$\cdots$ is a irrational number and 0.101001001$\cdots$ is a rational number. The cause of misconceptions is the definition of a irrational number defined by non-repeating infinite decimals. It is a cause of misconception about a irrational number that a irrational number is defined by a non-repeating infinite decimals and the method of using symbol dots in infinite decimal is not defined in text books.

• Journal of Educational Research in Mathematics
• /
• v.14 no.1
• /
• pp.1-17
• /
• 2004

According to the 7-th curriculum, irrational number should be introduced using repeating decimals in 8-th grade mathematics. To do so, the relation between rational numbers and repeating decimals such that a number is rational number if and only if it can be represented by a repeating decimal, should be examined closely Since this relation lacks clarity in some text books, irrational numbers have only slight relation with repeating decimals in those books. Furthermore, some text books introduce irrational numbers showing that $\sqrt{2}$ is not rational number, which is out of 7-th curriculum. On the other hand, if we use numeral 0 as a repetend, many results related to repeating decimals can be represented concisely. In particular, the treatments of order relation with repeating decimals in 8-th grade text books must be reconsidered.

• Journal of the Korean School Mathematics Society
• /
• v.25 no.4
• /
• pp.375-396
• /
• 2022

In this paper, to provide an idea for the 2022 revised mathematics curriculum by restructuring the content of the 2015 mathematics curriculum, the content elements of recurring decimals of textbooks, which showed differences in the curriculum of Korea and Japan, were analyzed. As a result of this study, in Korea, before the introduction of the concept of irrational numbers, repeating decimals were defined in the second year of middle school, and the relationship between repeating decimals and rational numbers was dealt with. In Japan, after studying irrational numbers in the third year of middle school, the terminology of repeating decimals is briefly dealt with. Then, when learning the concept of limit in the high school <Mathematics III> subject, the relationship between rational numbers and repeating decimals is dealt with. Based on the results of the study, in relation to the optimization of the amount of learning in the 2022 curriculum revision, implications for the introduction period of the circular decimal number, alternatives to the level of its content, and the teaching and learning methods were proposed.

• School Mathematics
• /
• v.1 no.2
• /
• pp.605-615
• /
• 1999

In this paper, we explain the pedagogical phenomena appeared in the learning of 0.$\dot{9}$ = 1 in terms of its intrinsic mathematical structure, and investigate the reason why such phenomena happen. Also we analyze such phenomena through the dialogue between student and teacher, and present some instruction idea from the mathematical and educational view points.

• The Mathematical Education
• /
• v.56 no.2
• /
• pp.131-145
• /
• 2017

The representation of irrational numbers has a key role in the learning of irrational numbers. However, transparent and finite representation of irrational numbers does not exist in school mathematics context. Therefore, many students have difficulties in understanding irrational numbers as an 'Object'. For this reason, this research explored how mathematics textbooks affected to students' understanding of irrational numbers in the view of process and object. Specifically we analyzed eight textbooks based on current curriculum and used framework based on previous research. In order to supplement the result derived from textbook analysis, we conducted questionnaires on 42 middle school students. The questions in the questionnaires were related to the representation and calculation of irrational numbers. As a result of this study, we found that mathematics textbooks develop contents in order of process-object, and using 'non repeating decimal', 'numbers cannot be represented as a quotient', 'numbers with the radical sign', 'number line' representation for irrational numbers. Students usually used a representation of non-repeating decimal, although, they used a representation of numbers with the radical sign when they operate irrational numbers. Consequently, we found that mathematics textbooks affect students to understand irrational numbers as a non-repeating irrational numbers, but mathematics textbooks have a limitation to conduce understanding of irrational numbers as an object.

• Journal for History of Mathematics
• /
• v.25 no.4
• /
• pp.1-10
• /
• 2012

In Chinese mathematics, there have been two numeral systems, namely one in spoken language for recording and the other by counting rods for computations. They concerned with problems dealing with practical applications, numbers in them are concrete numbers except in the process of basic operations. Thus they could hardly develop a pure theory of numbers. In Song dynasty, 0 and TianYuanShu were introduced, where the coefficients were denoted by counting rods. We show that in this process, counting rods took over the role of the numeral system in spoken language and hence counting rod numeral system plays the role of that for abstract numbers together with the tool for calculations. Decimal fractions were also understood as denominate numbers but using the notions by counting rods, decimals were also admitted as abstract numbers. Noting that abacus replaced counting rods and TianYuanShu were lost in Ming dynasty, abstract numbers disappeared in Chinese mathematics. Investigating JianJie YiMing SuanFa(簡捷易明算法) written by Shen ShiGui(沈士桂) around 1704, we conclude that Shen noticed repeating decimals and their operations, and also used various rounding methods.

• Communications of Mathematical Education
• /
• v.35 no.1
• /
• pp.119-136
• /
• 2021

We performed the research and education programs using engineering tools such as Mathematica, Microsoft Excel and GeoGebra for the students in mathematics mentorship program of the institute of science education for the gifted. We used the engineering tools to solve the problems and found the rules by observing the solutions. Then we generalized the rules to theorems by proving the rules. Mathematica, the professional mathematical computation program, was used to calculate and find the length of the repeating portion of the repeating decimal. Microsoft Excel, the spreadsheet software, was used to investigate the Beatty sequences. Also GeoGebra, the dynamic geometric software, was used to investigate the Voronoi diagram and develop the Voronoi game. Using GeoGebra, we designed the Voronoi game plate for the game. In this program, using engineering tools improved the mathematical creativity and the logical thinking of the gifted students in mathematics mentorship program.