Created by: Samantha Galvez, Escuela Isaac Alvarado, Monterrey, Mexico

Age group: Ages 8-12 (Grades 4-8)

Number of students recommended: 16 (ideal)

Subjects/skills learned: Geometry

Object of the game: The team that earns the most points (by forming geometric shapes) wins.

Setup: Divide the group in 2 teams. A stopwatch or chronometer is required. No information needs to be displayed or written on the tires. The teacher makes a list of geometric figures (roughly 6-8 of them, each shape corresponding to one round of the game).

Game Play: Flip a coin to decide which team begins. The first team goes to the edge of the playground. The teacher will announce a geometric figure (circle, square, ellipse, right triangle, isosceles triangle, etc). The team has to create the geometric figure asked by the teacher (the faster, the better!), by joining hands and standing on or next to tires (students may use the tires as points, or simply form the circle by holding hands in the shape without regard for the tires). The teacher notes the time in which the team correctly formed the shape. The second team steps up and does the same, the teacher calling out a different shape and noting the time. For that round, whichever team took less time to form their shape, is awarded one point. By the end, each team will have formed every shape on the list.

Game Conclusion: The team with the most points wins!

Examples: Team 1 makes a square in 2 minutes, Team 2 makes a rhombus in 2:15. Team 1 is awarded one point. The next round, Team 1 makes a right triangle in 3 minutes, Team 2 makes a trapezoid in 2 minutes. Team 2 is awarded one point.

Tips and Variations:

• Set a maximum time to create the shape.
• Instead of awarding points every round, tally up the total time to form all shapes at the end of all the rounds, and the team with the shortest cumulative time wins.