Skip to content # Game of Criss-Cross

## Activity Guide

# This guide goes into the underlying math of the game and provides a sample worksheet.

Vandervelde, Sam. (2020). Game of Criss-Cross. In S. Kohli (Ed.), Math Circle Activity Database. American Institute of Mathematics. https://mathcircles.org/activity/game-of-criss-cross

Contributor(s): Sam Vandervelde

Math Circles: MTC Network

- Activity Description
- Topics Covered
- Session Styles
- Mathematical Practices

The purpose for having students play the game of Criss-Cross is to motivate them to explain the underlying mathematical reason governing who wins or loses. This exploration should lead the students to form, test, and ultimately prove conjectures about how to win at Criss-Cross. The game illustrates a beautiful application of the Euler characteristic and gives them practice at elementary counting techniques as well.