School administrators across the nation are actively searching for solutions to increase student achievement due in part to the significant amount of knowledge that is lost annually each summer. Mathematical computation skills are especially at-risk. This quantitative research study was designed to investigate the impact of summer recess also known as summer vacation on mathematical computation skills. Assessing children in second and third grade from two different school calendars accomplished this on two separate occasions. First, children from a traditional calendar school and a balanced calendar school were assessed the last week of school respectively using a standardized benchmark assessment called the M-COMP. The same children were then post-tested using the same test following the summer recess. For the traditional calendar children the length of time between each assessment was 12-weeks. Participants from the balanced school calendar were posted-tested following a six-week summer recess. Dramatic results were revealed. [Pagination shown on provided PDF is incorrect.]