Students in the United States continue to struggle with explaining math concepts or their solutions to math problems, despite knowing how to solve the problems. Compared to other nations, these students have been shown to perform lower in math on state tests, specifically on portions where they have to engage in mathematical writing. The research problem addressed in this study was students' lack of ability to explain, in writing, how they obtain solutions to math problems. The purpose of the qualitative descriptive study was to explore how teachers in one district located in South Carolina use writing strategies to improve students' conceptual understanding of math. Vygotsky's zone of proximal development served as the theoretical framework. The participants included 16 general education math teachers and special education teachers in the South Carolina School District. The data were collected through semi-structured interviews and a focus group. Braun and Clarke's six-step reflective approach to thematic analysis was used to inductively analyze the data. Seven themes emerged from the data to depict the participants' descriptions of the phenomenon. They included visuals and writing scaffolds supporting students' ability to communicate math concepts and including open-ended questions on assessments to aid teachers in increasing students' understanding of math concepts. The results indicated that teachers need to support students with many writing scaffolds to assist them in writing their mathematical explanations, and they need to assess students with open-ended questions so that they can demonstrate their knowledge of mathematical concepts as well as improve their writing skills. By attending training sessions on integrating writing in their classrooms, math teachers can effectively provide opportunities for their students to use their reasoning skills to communicate mathematical concepts and their mathematical thoughts in writing. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]