In this article, the author examines the interconnection of two types of data driven decision-making: classroom and school. Each type seeks to improve teaching and learning, and both are important for supporting student achievement. The story of an elementary school that successfully used data to improve achievement scores of students in all subjects illustrates the use and benefits of data driven decision-making. The author argues that school leaders must use data from the big picture to gain a comprehensive understanding of the needs of all students in their schools.