The problem addressed through this study is the inconsistent use of mathematics educational technology tools in middle school mathematics courses in the United States. The problem was important to address because inconsistent use of mathematics educational technology tools may impact student performance. The purpose of this basic qualitative study was to explore middle school mathematics teachers' use of mathematics educational technology tools (i.e., IXL, i-Ready, and/or MATHia), the challenges they face, and their recommendations for other teachers. The constructivism concerns-based adoption model served as the conceptual framework. The three research questions were developed to investigate the purpose. Using purposive sampling, 11 middle school mathematics teachers from the United States who used the tool(s) were interviewed. The collected data were analyzed through coding, categorization, and theme identification. Findings revealed that teachers use these tools to monitor student progress via feedback mechanisms related to assessment, teaching, and practice. To use grading practices with the technology varied, with usage ranging from 45 minutes to 2.5 hours weekly, primarily in classrooms. Challenges included technology issues, alignment, administrative and professional development concerns, student behaviors, and student feelings. Teachers recommended strategies and professional development to enhance student learning experiences. Positive social change may result from the guides and recommendations provided in this study on consistent use of mathematics educational technology tools for teachers, which could lead to system-wide changes to ultimately increase student performance. [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.]