Factors influencing mathematics academic achievement are constantly changing and have direct and indirect effects on mathematics achievement, so longitudinal studies that can predict and analyze their growth are needed. This study uses longitudinal data on students from 2011 (5th grade of elementary school) to 2015 (2nd grade of middle school) of the Seoul Education Longitudinal Study, and divides them into groups with similar longitudinal changes in mathematics academic achievement. The direct and indirect effects of learning attitudes and achievement goals were examined. As a result of the study, it was found that learning effort and learning attitude had a direct effect on mathematics achievement in 1 group (2277 students, 67.7%), and learning attitude had a direct effect on mathematics achievement in 3 groups (958 students, 28.5%). And it was found that learning effort h ad an indirect effect. In addition, it was found that both learning attitudes, learning efforts, and achievement goals had no effect on the academic achievement of mathematics in the second group (127 students, 3.8%).

Despite the necessity and significance of mathematical competencies in the 2015 revised mathematics curriculum, there has been lack of studies analyzing textbooks in which such competencies are intended in detail through various tasks. Given this background, this paper analyzed how mathematical competencies and their sub-elements have been represented in the mathematics textbooks for third and fourth grade. The findings of this study showed that 'communication' was the most prevalent mathematical competence, followed by 'reasoning', 'creativity and integration', 'information processing', 'attitude and practice', and 'problem solving' in order. This study also explored the characteristics of mathematical competencies in the textbooks by analyzing which sub-elements per competence were popular. With illustrative examples, this paper is expected to provide for textbook developers with implications on how to represent mathematical competencies throughout the textbooks.

The purpose of this study is to confirm the influences of learner-centered instruction on learners' achievement and reason ability. In order to accomplish them, the fraction unit and the polygonal unit in the fourth grade were implemented with teaching methods and materials suitable for learner-centered mathematics instruction.
Some conclusions could be drawn from the results as follows:
First, learner-centered mathematics instruction has a more positive effect on learning of learned knowledge and generating unlearned knowledge in the experimental period than teacher-centered instructions. Second, learner-centered instruction makes an influence of low learning ability on getting achievement positively. Third, as the experimental treatment is repeated, learner-centered instruction has a positive effect on students' reasoning ability. The reasoning ability of students showed a difference in the comparison between the experimental group and the comparative group, and within the experimental group, there was a positive effect of the extension of the positive reasoning ability. Fourth, it can be estimated that the development of students' reasoning ability interchangeably affected their generation test results.