Filter by:


Supporting materials


Session Styles

Mathematical Practices


Math Sessions

Don’t see what you’re looking for? Check our legacy math sessions page.
For best results on mobile, use desktop view
Submit a Session

Chris Bolognese, Raj Shah
Is it possible to measure all possible integer lengths on a ruler without marking every integer on that ruler? This is an engaging and challenging problem for all. Beautiful mathematics can be revealed while delving deeper into this rich mathematical task.
Japheth Wood, Paul Ellis, Samuel Coskey
Are there more fractions than counting numbers? Surprisingly, an investigation into binary notation can help us answer this question! This session explores the binary number system. Participants will investigate Hyperbinary numbers, create a Fraction Tree, and discover connections between them.
Judith Covington
A pentagonal tiling is a tiling of the plane where each individual piece is in the shape of a pentagon. The plane cannot be tiled with regular pentagons. However, are there any convex pentagons that can tile the plane? This session explores various pentagons and their tiling abilities.
Catherine Pullin Lane, Lynne Pachnowski
The game of Tic-Tac-Toe has roots going back centuries. Grid-style game boards have been found in Ancient Egypt, during the Roman Empire, and in our current age on restaurant placemats. Multiple avenues of exploration are possible with this simple children's game. A related game called “Gobblet Gobblers” takes Tic-Tac-Toe to a whole new level!
Chris Bolognese, Emily Dennett
College students need to be matched with a roommate. They each make a list of who they prefer to room with. Given the preference lists for each individual, can we find a matching that is stable? That is, would any pair ask to change rooms because they would rather room together than with their current roommates? Explorations lead to new questions or new avenues to investigate using various mathematical methods including, but not limited to, combinatorics, graph theory, or matrices.
Gene Abrams
A Mad Veterinarian has created three animal transmogrifying machines… While grappling with the posed questions, players will explore a set of problems, figuring out how and if the machines can complete a given transformation. Connections can be made to invariants, abstract algebra, graph theory, and Leavitt path algebra.
Hanna Bennett, Nina White
Can you find all possible semiregular tilings of the plane? A tiling of the plane covers the (infinite) plane, without gaps or overlaps, using congruent copies of one or more shapes. A semiregular tiling is a tiling of the plane with certain constraints: two or more regular polygons are used, polygons meet edge-to-edge, and the pattern of polygons around every vertex is the same.
Craig Collins, Cynthia Kramer, Elizabeth Donovan
How many different ways are there to make change for a dollar? As mathematicians we often search for patterns in a problem. However, for this problem, there is no simple, predictable pattern to build to an answer, encouraging participants to reach outside their comfort zones and ponder alternative strategies in order to make progress.
Elizabeth Livorsi, Maureen Aguglia, Sara MacKenzie
Developed as part of the Math Circles of Inquiry project, this module is an introductory activity for rational numbers, likely aligned with Grade 7. Students will be given five points on a number line and will be asked to estimate the values of each in a 3-part task and explain their reasoning. The activity is designed to have students then fluently add, subtract, multiply, and divide these rational numbers and justify the placement of their solutions on the number line.
Matt Roscoe
Quilts are a familiar set of cultural artifacts for many people. Quilts also happen to be beautifully mathematical. “What sorts of symmetries can a quilt block possess?” Participants will design and examine quilt blocks, and develop a taxonomy of symmetry in order to compare the blocks according to the symmetries, both present and absent.