Through KenKen puzzles, students can explore parity, counting, subsets, and various problem-solving strategies.
Using KenKen to Build Reasoning Skills
Harold B. Reiter, John Thornton, and G. Patrick Vennebush
Improving Student Reasoning in Geometry
Bobson Wong and Larisa Bukalov
Parallel geometry tasks with four levels of complexity involve students in writing and understanding proof.
Thinking Like a Mathematician
Michael K. Weiss and Deborah Moore-Russo
The moves that mathematicians use to generate new questions can also be used by teachers and students to tie content together and spur exploration.
Is There a “Best” Rectangle?
R. Alan Russell
In trying to find the ideal dimensions of rectangular paper for folding origami, students explore various paper sizes, encountering basic number theory, geometry, and algebra along the way.
Teaching the Perpendicular Bisector: A Kinesthetic Approach
Through movement-a welcome change of pace-students explore the properties of the perpendicular bisector.
Proofs without Words: A Visual Application of Reasoning and Proof
Carol J. Bell
Reasoning and Proof is one of the process standards set forth in NCTM's principles and standards for school mathematics (2000).