The focus of the Uncovering Student Thinking in Mathematics resources is on asking the right question. Writing a good formative assessment probe is very different from writing appropriate questions for summative tests or state and national exams. Formative assessment questions need to be designed to elicit prior understandings and commonly held misconceptions. This elicitation allows the educator to make sound instructional choices based on the specific needs of a particular group of students. Use of these formative assessment probes allows educators to maximize the potential of their math program materials by illuminating student understanding through a finer lens. The first three Uncovering resources provide a sample across the K-12 spans for each of the content areas of the NCTM standards. Although the NCTM standards continue to be important, educators are primarily focusing on the Common Core Standards for Mathematics (CCSM). Mathematics leaders are working hard to develop tools and methods to deepen educators' understanding of the CCSM standards including understanding the learning progression within the standards and the mathematical practices that describes the processes and proficiencies that need to be developed throughout the grade spans. Uncovering: Common Core Connection will bring to the mathematics education field an important tool that connects formative assessment, active research, the CCSM standards, and mathematical practices.