Just like physical skills, cognitive skills grow rusty over time unless they are regularly used and practiced so academic breaks can have negative consequences on student learning and success. The Keeping in School Shape (KiSS) program is an engaging, innovative, and cost-effective intervention that harnesses the benefits of retrieval practice by using technology to help students maintain proficiency over breaks from school by delivering a daily review problem via text message or email. A growth mindset is promoted through feedback messages encouraging students to try again if they get a problem wrong and to take on a challenge problem if they get a problem correct. This paper reports on the relationship between confidence, accuracy, and decision making during the implementation of the KiSS Program at a large university during winter break for students enrolled in an engineering introductory Calculus course sequence. [For the complete proceedings, see ED630060.]