In light of technological development worldwide, the focus has been on how different types of digital technology can be used to provide activities that will enhance students' mathematical learning. Micro-learning is an innovative approach that will accelerate digitalization in mathematics teaching, attract students to mathematics, and combine technology and mathematics education. The study aims to reveal the effect of micro-learning teaching of the middle school 6th-grade mathematics lesson "Ratio" on students' conceptual and procedural knowledge. In the study carried out within the scope of qualitative research, the case study research design was preferred. In the study group, ten students studying in the 6th grade of middle school were studied. In the research, the conceptual and procedural knowledge definitions of the "Ratio" subject created by the researchers were created by reviewing the literature, and the status of the interview was examined based on the data obtained at the end of the study. During the data collection phase of the research, the Conceptual and Procedural Knowledge Test (CPKT) developed by the researchers and interviews with two students were used. The collected data was analyzed by content analysis. After the micro-learning teaching in the e-learning environment, it was seen that there was a 76% success rate in the procedural knowledge of the students, in which they generally acquired the conceptual knowledge of the "Ratio" subject. Thus, it has been demonstrated that micro-learning can be used in mathematics lessons.