Skip to content# Game of Criss-Cross

**Classifications**

Author(s): Sam Vandervelde

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.

Session styles: Multiple Representations, Try a Smaller Problem

Supporting materials: Facilitator Guides

Associated Math Circles: MTC Network