Public Lectures with Leverhulme Visiting Professor Helena Osana

Finding One: Units in the Elementary Mathematics Curriculum - 20 May, 4pm-5pm

A unit is what we call “one.” This lecture examines where “one” appears—and often hides—in the elementary mathematics curriculum. It traces how units structure the big ideas in elementary mathematics, including numeration and place value, multidigit arithmetic, multiplication and division, and fractions. The talk highlights how seemingly disparate domains in school mathematics are tied together by unit concepts and how understanding in mathematics is dependent on flexible and relational reasoning about units and “oneness.”

Understanding One: Challenges in Children’s Understanding of Units - 10 June, 2pm-3pm 

This lecture focuses on children’s understanding of units from early counting to more advanced concepts involving measurement and composite units. It reviews research on how children construct the idea of “one” as both a countable entity and a unit that can be iterated and nested within higher-order structures. Common difficulties are examined, including treating collections of units as wholes, coordinating multiple units, and understanding numbers as a structure of embedded units. Together, these perspectives provide a nuanced account of why unit concepts are persistently challenging.

Supporting One: Supporting Children’s Unit Understanding - 7 July, 2pm-3pm

This lecture explores how learning environments and instructional approaches might support the development of robust unit understanding in children. The lecture will describe what is known about how environmental factors, such as visual representations and narrative, may play a role in children’s interpretation of “oneness” and in coordinating groups of discrete elements into structured, countable units. Promising early evidence will be presented on how to support children’s learning of embedded units in base-ten through instruction that explicitly foregrounds unit structure and supports analogical mapping across representations. Implications for curriculum design and classroom practice will be addressed.