Nonverbal proofs are diagrams or illustrations that will help us see what a mathematical expression means, why it is true, and how it is proved. The aim of this study is to examine the effects of nonverbal proof-based education on preservice mathematics teachers. The study was conducted using case study research methods, one of the qualitative research designs. The participants of the study consisted of 31 preservice mathematics teachers. The data were collected in writing at the beginning and end of the process with questions directed to preservice teachers. These questions in the data collection tool were used to compare the responses of the preservice teachers who had an experience with nonverbal proof in the pre and post assesment and compare the changes. In the analysis of the data, descriptive analysis, which is a qualitative data analysis, was used. Firstly, each preservice teacher’s responses in the post assesment are classified according to their similarities and differences and then are categorized. Then, the answers in the pre assesment were examined and the responses were compared whether there was a change or not. The findings of the study showed that the preservice mathematics teachers’ experience of nonverbal proof effect on the recognition of the given image and establishing a relationship with different mathematics subjects.

Nonverbal proofs are diagrams or illustrations that will help us see what a mathematical expression means, why it is true, and how it is proved. The aim of this study is to examine the effects of nonverbal proof-based education on preservice mathematics teachers. The study was conducted using case study research methods, one of the qualitative research designs. The participants of the study consisted of 31 preservice mathematics teachers. The data were collected in writing at the beginning and end of the process with questions directed to preservice teachers. These questions in the data collection tool were used to compare the responses of the preservice teachers who had an experience with nonverbal proof in the pre and post assesment and compare the changes. In the analysis of the data, descriptive analysis, which is a qualitative data analysis, was used. Firstly, each preservice teacher’s responses in the post assesment are classified according to their similarities and differences and then are categorized. Then, the answers in the pre assesment were examined and the responses were compared whether there was a change or not. The findings of the study showed that the preservice mathematics teachers’ experience of nonverbal proof effect on the recognition of the given image and establishing a relationship with different mathematics subjects.