Connecting Mathematicians of All Ages

# Activity Collections for Math Teacher Circles

Math Teacher Circles (MTCs) are communities of K-12 and higher education mathematics professionals who meet regular to engage in the collaborative investigation of non-routine, rich, low-threshold, high-ceiling problems, and to reflect upon their experiences as practitioners of mathematics and teaching (Hendrickson, 2016Taton, 2015).

Pedagogically, MTC facilitators should strive to model high-leverage instructional practices such as supporting learners in productive struggle (jokingly referred to as “funstration” by the MTC community), posing purposeful questions, and encouraging meaningful mathematical discourse. For a great overview of the mathematical philosophy of MTCs, see the article “Be Less Helpful” by Joshua Zucker. Organizers should also check out our MTC Toolkit for additional tips.

Below you’ll find collections of some of our favorite MTC activities!

## Grid Power

“When I grew up in the Soviet Union, all we used for math was grid paper. Grid paper leads to discovery.” This is how Tatiana Shubin, San Jose State University, begins her lesson demonstrating the myriad of wonderful math questions arising from a simple sheet of grid paper. Attempting to...

## Acting Out Mathematics

In teams, participants will create body movements related to geometry facts and will use their body to create a convincing argument as to why the statement is true. Please bring your fun-meter, your creativity, your body, and open physical space (for moving) to this session.

## Folding Perfect Thirds

Imagine you’re packing for a trip, and you’re planning on bringing your favorite tie. It’s too long to fit in your suitcase, even after folding it in half. You would fold it into fourths, but you don’t want all of those creases ruining your tie. You’ve decided folding it into...

## Factor Game

A teacher challenges students to a game. The rules are explained as the game progresses. The player with the highest total wins! Students then play against each other. Afterwards, while analyzing the game, prime, composite, perfect, deficient, and abundant numbers are discovered and defined. Students again play the game using...

## Measuring Up: “Perfect” Rulers

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 seemingly easy question.

## Conway’s Rational Tangles

What do adding positive and negative fractions have to do with tying knots? In this entertaining lesson, students will use ropes to explore and identify mathematical operations that untangle knots and lead to new thinking. Simple operations of twists and rotations circle back to practicing the addition of positive and...

## The Game of SET

SET is a fun game that can be enjoyed by kids as young as 6 and is challenging even for adults. It is rich in counting problems and is great for getting people to pose problems. It is also an example of a finite geometry and interesting to explore how...

## Prejudiced Polygons

Triangles and Squares live together in neighborhoods. However, the Polygons all believe two things: “I am unhappy if fewer than 1/3 of my immediate neighbors are like me.” and “I am unhappy if I have no immediate neighbors.”