When applied to mathematics education, manipulatives help students to visualize mathematical concepts and apply them to everyday situations. Interest in mathematics instruction has increased dramatically over the past two decades with the introduction of virtual manipulatives, as opposed to the concrete manipulatives that have been employed for centuries. This quasi-experimental study proposed to explain the relationship between concrete and virtual manipulatives when used in a seventh-grade mathematics classroom. Using students' mathematics composite scores on standardized and teacher-created assessments, it compared the effectiveness of using concrete manipulatives alone versus using a combination of concrete and virtual manipulatives. The foundational theory of the study is that when students can visualize a mathematical concept in action, a deeper level of understanding occurs. The results of this mixed methods study consisting of 44 seventh-grade students (22 in each group) indicated that coupling concrete manipulatives with virtual manipulatives led to a measurable change in mathematics composite scores. One recommendation is that mathematics educators incorporate both concrete manipulatives and virtual manipulatives into their mathematics curriculum. As the results of this year-long study indicated, the combination of these two types of manipulatives enabled the students in this group to accomplish a measurable change in tested mathematical ability. Educators need to offer their students lessons that are authentic and interesting in order to hold students' attention as they attempt to grasp the concepts. The different options also provide students with the needed differentiated instruction to suit their varied learning styles. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]