Community Service Activities are mandatory activities carried out by UIN North Sumatra students, especially at the Faculty of Tarbiyah and Teacher Training. PMM-4 students carry out community service activities in Bandar Magodang Village, Bintang Bayu District. One of the series of activities planned by PMM-4 students is a study house which is attended by the children of Bandar Magodang Village. This study house program aims to help the children of Bandar Magodang Village in brushing and maintaining good and correct dental health. This program is running well, this service activity is carried out through 3 stages, namely planning, implementation and evaluation. The method used in implementing this community service is a qualitative approach. Data were collected before and after the intervention to assess changes in children's knowledge and behavior. The results showed a significant increase in their understanding of the importance of brushing their teeth properly and maintaining dental health in general. The implication of these findings is the importance of ongoing dental health education in rural communities to improve children's dental well-being. This learning house action was completed on 18-19 August 2023 in one of the residents' yards in Bandar City, Bintang Bayu District.

The purpose of this research is to find out about students' mathematical abilities and proofs when learning mathematics at the tertiary level. In this research, researchers used quantitative methods in the form of literature reviews or literature reviews, namely this research took data sources from books, journals and previous research that had been carried out. Apart from that, it is also based on the results of the researcher's analysis, where this theoretical reference can be used as a strong basis for understanding students' mathematical proof abilities. Based on the research results obtained by researchers, it is that students' mathematical proof abilities are not optimal, and based on the research results, the percentage of mathematical proof abilities obtained is less than optimal. The majority of students still have difficulty working on proof questions. This is due to various factors, one of which is that understanding of integers and their definitions and properties is still low.