In this article, one teacher describes her action research with eighth-grade prealgebra students who are working on a conceptual understanding of fractions. Examining her middle school students' standardized test scores for the previous five years, Denise S. Peppers discovered that student performance on fractions was consistently the lowest of all concepts in grades 5-8. Consistent with research, students often struggled with a conceptual understanding of fractions. Based on a review of literature on manipulatives (a manipulative is an object which is designed so that a learner can perceive some mathematical concept by manipulating it) and patterns of misconceptions in student work that Peppers had seen over the years, she designed a unit of instruction using concrete and virtual manipulatives. Concepts in the unit included fraction equivalences/relationships, ordering fractions, and dividing and multiplying fractions in context. Throughout the unit, the students used a variety of concrete as well as virtual manipulatives. Because of the positive results from the project, Peppers continued to incorporate concrete and virtual manipulatives into regular instruction throughout the year and focused on critical thinking skills as the students covered the standards. Students' attitudes toward math continued to improve; their ability to communicate their understanding improved; and, subsequently, they were able to build on the knowledge they gained during their unit lessons. Pepper concludes that using both concrete and virtual manipulatives helped her recognize the importance of knowing which manipulatives were useful with particular concepts, as well as the limitations. Each year, Pepper reports she has tried to improve the methods of instruction to meet students' needs and that seeing students' enthusiasm for learning gave her encouragement to continue improving her methods of instruction using manipulatives.