Abstract
The presented research will focus on the construction of real numbers (R) through Dedekind cuts its use in education, with experiences in high school classes at a public school in São Carlos. The overall objective of the research is to establish the topic based on theoretical foundations and apply some results in the development and implementation of lesson plans in the classroom. The methodology to be employed includes bibliographical research and field research with diary recording of school experiences. Consequently, it is expected that, after the analysis and documentation of the experiences, the mathematics in basic education.