Mathematics is the language and foundation for the science, engineering, and technological fields that define and enhance our lives in the 21st century. Proficiency in math requires problem solving, logical reasoning, and critical thinking skills that are essential to success in college, the workplace, and everyday life. Unfortunately, math has also proven to be a difficult subject to teach well in schools in the United States. Students who excel in the subject are likely to do well in college and the workforce, while those who do not may well be left out of many opportunities that support satisfying and successful lives. The need for students to perform well on standardized math tests often causes schools to narrow their curriculum to only what will be tested and to rely on traditional methods of instruction that involve lectures, worksheets, and tests to cover all the material. Too often, the result is that students become less engaged in the lessons and less likely to enjoy learning math. This study attempted to determine whether the use of project-based learning in a middle school math class would increase students' engagement in the lessons and improve their attitudes toward learning math while still covering required content. Working in cooperative groups, students carried out their own investigations involving data collection, analysis, and presentation of findings. Changes in student attitudes and engagement levels were determined through student surveys, researcher observations, and focus group interviews, and the results were used to make policy recommendations for the school district. [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.]