U of A mathematics professor Chaim Goodman-Strauss, winner of the 2021 Rosenthal Prize for Innovation and Inspiration in Math Teaching, recently shared his award-winning lesson with a class of future teachers.

Goodman-Strauss taught students from the STEM Education and Master of Arts in Teaching programs about rotational symmetry. Shapes and objects have rotational symmetry if they still look the same after less than one complete turn and have no mirror symmetry. Students created paper "tiles" with four different points of two-fold rotational symmetry that they placed in a tessellation pattern that could fill an infinite space. This specific symmetry, called 2222 symmetry because of the four points of two-fold symmetry ("tooti tooti" for short), is one of 17 infinite planar types in the Euclidean plane.

Questions such as "What is a rule for how the tiles fit together?" and "How many different kinds of 2-fold rotation points are there in the pattern?" were used to generate conversation about this particular symmetry and to model the kind of questioning that is expected in mathematics classrooms.

"Dr. Goodman-Strauss enthusiastically accepted the invitation to speak to my class," said associate professor Kim McComas, instructor of the secondary mathematics teaching methods course. "A central purpose of the Rosenthal Prize is to disseminate innovative teaching ideas widely."

U of A student Ashtyn Adams, an intern teacher at Don Tyson School of Innovation in Springdale, requested Goodman-Strauss' materials after the lecture. She said she'd like to use them in an upcoming eighth-grade math unit. 

Student Kendyal Free, who's interning at Fayetteville High School, said, "I thought the class with Dr. Goodman-Strauss showed me a way to connect to some students who may be hard to reach."

Most of the teacher candidates who attended the presentation had previously taken Goodman-Strauss' courses as part of their math studies programs. "The reunion was appreciated by all," McComas noted.

The Rosenthal Prize for Innovation and Inspiration in Math Teaching is sponsored by the Museum of Math in New York City.