Recess is a vital piece of the elementary school day. The impact of this time extends beyond students' physical, emotional, and social health. Recess has also been shown to have a positive impact on the classroom performance of students. The purpose of this causal comparative study was to test the theory of the impact of recess in elementary school that relates to the scheduling of mathematics directly after recess time to achievement on a standardized mathematics assessment for third grade students in Central Virginia. Grade level and assessment type were controlled for in this study. Participants were third grade students from one school division in Region Five of Virginia. The students were divided into two groups: students who participated in an unstructured recess break directly prior to mathematics instruction and students who did not have an unstructured recess break directly prior to mathematics instruction. The researcher collected archived Third Grade Mathematics Standards of Learning Assessment scores for participating students and used a two-way ANOVA to analyze the data. The results of the two-way ANOVA showed no significant difference between the means of students who had mathematics class after an unstructured recess time and students that did not have mathematics after an unstructured recess time. Male students scored significantly higher than female students regardless of the timing of mathematics instruction. Recommendations for future research include further exploration of gender difference in elementary mathematics and the impact of unstructured recess breaks using a different measure of academic achievement. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]