Schools are expected to ultimately moderate the difference of inequality issues among social groups and reduce the achievement gaps. This study investigates this expectation, in particular, how students' mathematics achievements are influenced by their parents' education at the individual level and by collective responsibility for teaching at the school level as well as the interaction of the two. Using a two-level hierarchical linear model, this study indicates that a school collective responsibility has a larger positive effect on students' mathematics achievement when their parents' education level is high. This means that school's collective responsibility accelerates inequity in students' mathematics achievement. Knowing that collective responsibility has less of an effect on students whose parents' education is not high, researchers, schools, and school districts should continue to search for school effects that have more of a positive impact on the relationship between mathematics achievement for students whose parents' education is not high in order to have more equitable results for all students.

The purpose of this study is to analyze the multiplication units in the elementary school mathematics. In the 2015 revised curriculum, students learn multiplication in $2^{nd}$ grade. The multiplication units is divided into two: multiplication and multiplication facts. In these two units, we mainly analyze situations involving multiplication, models for teaching multiplication, and multiplication strategies for teaching multiplication facts in relation to Subject Matter Knowledge. We called these contents Multiplication Matter Knowledge. We examined the precedent study with regard to multiplication at the elementary mathematics. As results, we prepared an analysis framework for this study. This study was conducted according to qualitative research methods, expecially 'qualitative contents analysis'. The contents here refer to Multiplication Matter Knowledge that can be found in the elementary mathematics textbooks and working books etc. As results of analysis, We can confirm that various multiplication situations and multiplication models are presented in the textbooks. And it has been examined that various multiplication properties are presented in the textbook according to the multiplication strategy levels. We insist elementary school teachers should be aware of these Multiplication Matter Knowledge. This study aims to provide elementary school teachers with basic data in these contexts.

The purpose of this study is to investigate how students' mathematical creativity changes through problem-solving instruction using problem-posing for elementary school students and to explore instructional methods to improve students' mathematical creativity in school curriculum. In this study, nonequivalent control group design was adopted, and the followings are main results. First, problem-solving lessons with problem-posing had a significant effect on students' mathematical creativity, and all three factors of mathematical creativity(fluency, flexibility, originality) were also significant. Second, the lessons showed meaningful results for all upper, middle, and lower groups of pupils according to the level of mathematical creativity. When analyzing the effects of sub-factors of mathematical creativity, there was no significant effect on fluency in the upper and middle groups. Based on the results, we suggest followings: First, there is a need for a systematic guidance plan that combines problem-solving and problem-posing, Second, a long-term lesson plan to help students cultivate novel mathematical problem-solving ability through insights. Third, research on teaching and learning methods that can improve mathematical creativity even for students with relatively high mathematical creativity is necessary. Lastly, various student-centered activities in math classes are important to enhance creativity.

This study is a basic study for developing a mathematical learning application program that can be used in smart devices for adaptive learning. We selected 20 mathematical learning applications including middle school contents and analyzed learning types. And we analyzed the contents and the learning process. As a result, most learning types of mathematics learning applications were problem-centered. Contents analysis results showed that the most applications have achievement goals. The factors that induce interest in learning were lacking and feedback was not provided sufficiently. Analysis of the learning process showed that most of the math learning applications were classified according to their purpose and characteristics.

This is a descriptive study with the intent of providing a rich characterization of teachers' perceptions of rate of change. The nature of teachers' perceptions and differences among teachers were examined by collecting data through a survey on teachers' conceptions of rate of change in terms of learning goals, prerequisites, and beliefs about teaching and learning of rate of change, and an interview individually assessing teachers' concept images and definitions. The participating 13 teachers were selected to provide a range of similar and contrasting levels of experiences based on the teachers' educational background and the number of years they had been teaching. Findings and implications of this study are discussed.

This study reports the history of abacus calculation in the East and West and the changes in the curriculum of abacus calculation in Korea. The findings from this study are that abacus calculation education program already disappeared from public education and that it depends on private education institutes or after school classrooms. According to a case study, of the 110 elementary schools located in Changwon City and Gyeongsangnam-do Province, 74 schools were educating abacus as after-school programs.

This paper studies the relationship between the college entrance examination scores and college mathematics achievements of the freshman, who are the students of college of technology and management in Yanbian University, by employing statistical analysis. First of all, we start from the correlation analysis of the majors and regions of students. Secondly, with gender and region as the classification, we divide the sample into two parts and test the mean significance, and we find that not only different gender but also different region have significant differences to college mathematics achievements. Thirdly, we use the college entrance examination scores as independent variable, and college mathematics achievement as the dependent variable to establish regression model. The model provides a realistic basis for the education department of our school, and provides reference value for the other major research.