DIY normal distribution

Author: Judit Mokos

Recommended age: 14-99

Number of players: 10-30

Space needed for the game: classroom or other open space

Difficulty level: 1

Playing time: 10 minutes

Preparation time: 2 minutes

Accessories: All players need a coin.

Short description: In nature, several phenomena show normal or Gaussian distribution. In this game we will simulate such a phenomenon and show how the corresponding normally distributed dataset could appear.

Preparations: All players need a coin.

Course of the game: The players stand in a row at one side of the classroom, facing the other side. All the players have a coin in their hands. They flip the coin, and those who got head step forward, those who got tail remain at their place. Stop the game after 20 rounds (or if you have more time, later). Preferentially, all players should remember the number of steps they moved. Discuss that only a small proportion of the players reached the other side of the room or stayed at their original position. Most of the players are standing somewhere in the middle. If you have a blackboard you can make a graph about the observed results: put the number of the steps on the X axis, and number of players who managed to do the given amount of steps on the Y axis. The more players we play this game with, the more similar this graph will be to the bell-shaped normal distribution’s histogram. After the game we can have a discussion with the players about what phenomena show normal distribution in nature. We can collect the height of the players and draw a similar graph to see that the heights of humans show a normal distribution as well.

Biological background: The normal distribution appears in several situations in nature. The heights and weight of humans and other animals and plants, the blood pressure, and the IQ score are all normally distributed. This game helps to understand how a normal distribution could be created by chance.

References: own idea