Teaching conditional probability in grade 12 using realistic mathematics education theory

The perspective on applying mathematics to solve practical problems is clearly expressed in Vietnam's Mathematics General Education Curriculum in 2018. Therefore, Realistic Mathematics Education (RME) is suitable for the goals of mathematics education in Vietnam and can become one of the fundamental theories for designing mathematics teaching models in high schools. This study presents an experimental result of teaching conditional probability based on RME and following a five-step process we develop, including problem setting, experience, rediscovering conditional probability, forming conditional probability, application. Worksheets containing problems were distributed to 42 students to solve, and their work was collected immediately afterwards. The works will be analyzed to identify emergent models constructed by students. The new result of the paper is from the study of De Lange, Jupri and Drijvers, we propose a mathematization process for teaching conditional probability in Vietnam. The data analysis method is a qualitative method, through observing the students' problem-solving process. Experimental results show that students actively participated in the process of reinventing conditional probability through solving learning tasks.