José N. Contreras
Rick Anderson and Peter Wiles
Recognizing the complex nature of students’ geometric reasoning, we present guidelines and suggestions for implementing a Guess My Shape minilesson that focuses students’ attention on properties and attributes of geometric shapes.
Deanna Pecaski McLennan
For the Love of Mathematics
Using technology to solve triangle construction problems, students apply their knowledge of points of concurrency, coordinate geometry, and transformational geometry.
Ryota Matsuura and Yu Yan Xu
This activity involves finding the distance between two points in a coordinate plane and emphasizes reasoning from repeated calculations, which is one of the mathematical practices specified by the Common Core State Standards for Mathematics.
Kevin C. Moore and Kevin R. LaForest
A connected introduction of angle measure and the sine function entails quantitative reasoning.
Agida G. Manizade and Marguerite M. Mason
When calculating the area of a trapezoid, students use a range of problem-solving strategies and measurement concepts.
Hyewon Chang and Barbara J. Reys
Using Clairaut's historic-dynamic approach and dynamic geometry tools in middle school can develop students' conceptual understanding before they encounter formal proof in geometry.
Harold B. Reiter, John Thornton, and G. Patrick Vennebush
Through KenKen puzzles, students can explore parity, counting, subsets, and various problem-solving strategies.
Students fold paper to make and test conjectures while reasoning about and discussing geometric ideas.