Developing mathematical proficiency in junior high school: A case study on linear equations in one variable

This study aimed to support the development of mathematical proficiency in Junior High School students, especially on linear equations in one variable. This research is a case study in two public schools in Bandung, Indonesia, involving 50 class VII Junior High School students. This qualitative study collects data from test results and reviews documentation results. The data were analyzed with instrument validity, data collection, data reduction, data presentation, and concluding stages. The result showed 1) Students achieve the category of high mathematical proficiency in conceptual understanding with a percentage of 81%; 2) Students achieve the category of high mathematical proficiency in procedural fluency with a percentage of 87%; 3) Students achieve the category of moderate mathematical competence in strategic competence with a percentage of 67%, 4) Students achieve high mathematical skills in the category of adaptive reasoning and productive disposition with a percentage of 96%. This is due to the teacher’s proper design of learning and learning flow and anticipating every student response that appears in the learning process. The learning design starts from understanding the concept of closed sentences and open sentences, forms of similarities and equations, understanding, solving, and using linear equations in one variable everyday life. This research impacts the development of mathematical proficiency in the material of good students’ linear equations in one variable.