Introduction: Probing Beneath the Surface of Experience -- Teacher Noticing in Various Grade Bands and Contexts: Commentary -- From a Framework to a Lens: Learning to Notice Student Mathematical Thinking -- Investigating Secondary Preservice Teacher Noticing of Students' Mathematical Thinking -- A Case Study of Middle School Teachers' Noticing during Modeling with Mathematics Tasks -- Using Video of Peer Teaching to Examine Grades 6-12 Preservice Teachers' Noticing -- Examining Student Thinking through Teacher Noticing: Commentary -- Mathematical Teacher Noticing: The Key to Learning from Lesson Study -- Learning to Notice Student Thinking about the Equal Sign: K-8 Pre-service Teachers' Experiences in a Teacher Preparation Program -- Following a Teacher's Mathematical and Scientific Noticing across Career Progression from Field Experiences to Classroom Teaching -- Noticing Students' Conversations and Gestures during Group Problem-Solving in Mathematics -- Extending Equitable Practices in Teacher Noticing: Commentary -- "Everything Matters": Mexican-American Prospective Elementary Teachers Noticing Issues of Status and Participation While Learning to Teach Mathematics -- "Maybe It's a Status Problem." Development of Mathematics Teacher Noticing for Equity -- Making Visible the Relationship between Teachers' Noticing for Equity and Equitable Teaching Practice -- Complexities in Measuring Teacher Noticing: Commentary -- Measuring Noticing Within Complex Mathematics Classroom Interactions -- Using Mathematical Learning Goals To Analyze Teacher Noticing -- Measuring Elementary Mathematics Teachers' Noticing: Using Child Study as a Vehicle -- Investigating the Relationship Between Professional Noticing and Specialized Content Knowledge -- A Standardized Approach for Measuring Teachers' Professional Vision: The Observer Research Tool -- Challenges in Measuring Secondary Mathematics Teachers' Professional Noticing of Students' Mathematical Thinking -- Exploring the Boundaries of Teacher Noticing: Commentary -- Shifting Perspectives on Preservice Teachers' Noticing of Children's Mathematical Thinking -- Curricular Noticing: Theory on and Practice of Teachers' Curricular Use -- The FOCUS Framework: Characterising Productive Noticing during Lesson Planning, Delivery, and Review -- Noticing Distinctions Among and Within Instances of Student Mathematical Thinking -- Teachers' Professional Noticing from a Perspective of Key Elements of Intensive, One-to-one Intervention -- The Ascendance of Noticing: Connections, Challenges, and Questions .