In the mid-1960s, educational lawmakers began passing and implementing plans to raise the achievement of all students across the United States. In these early years of education mandates, the federal government became more involved in public education. Education lawmakers began to focus on struggling learners and how teachers could support those struggling learners and were willing to give federal funding to those attempting to raise the level of achievement in underperforming schools. In light of the scarcity of research on supporting diverse learners at the middle school level, researchers began studying how teachers could better support this new and diverse population of learners. Due to the absence of relevant literature on teachers' perceptions' of middle school mathematics students' abilities and how those perceptions influenced teachers' planning and implementation of classroom activities, I designed this qualitative, interpretative study to examine the perceptions of middle school teachers in the First Grand Division of Tennessee regarding students' academic abilities in mathematics and how those perceptions influence teachers' planning and implementation of classroom activities. I sent questionnaires to 58 middle grade teachers and received responses from 20 participants. I found teachers' perceptions of students' academic abilities where most students were below grade level and had gaps in mathematical abilities. The results revealed half of all teachers did not have planning partners, and 8 out of 20 participants reported having limited to no support from instructional leaders in planning lessons. [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.]