The following lesson plan is designed to give an introduction into the wonderful world of STELLA. Students will partake in Stella by first watching the teacher build a successful model. Then students will be given the opportunity to change some of the data in the model to see changes in the outcome of the model. If you haven't had any experience with Stella thus far, please refer to the tutorial provided Here!

To begin the lesson, make sure each computer in which pairs of students use has Stella on it. As well as the Healthy vs. Sick Stella model, in which the students will be exploring. It can be found Here! You should explain to the students the basis behind Stella and what a great modeling tool it is.

Before you actually begin the Stella activity, have students get in groups of 3 to 4. We will attempt to model the Healthy vs. Sick problem using dice and marbles. If you do not have access to any marbles feel free to cut out several small pieces of paper, of red and blue (or any other 2 colors). In this warmup, students will have a pile of red marbles and a pile of blue marbles. The red marbles represent the sick kids, while the blue marbles represent the healthy students. Explain to the class that all these students healthy and sick go to the same school and have interaction with each other and that there is a likelihood of 1/3 that a sickly student will cause a healthy student to become sick.

The goal of the game is to make all the healthy students become sick. This will take place by, for every sick student in the red pile will gain the opportunity to roll a die. The students should have already had an introduction to probability, so make sure they understand 1/3 = 2/6. Therefore, tell the students to select 2 numbers on the die, which will represent a student spreading their flu. Each time a sick student rolls the die, and contaminates another student that blue marble will now become a red marble. Continue this proccess on untill each of the blue marbles have become red. Make sure you have a student recording the data of how many marbles there are each round, and how many steps it takes to contaminate everyone. The number of marbles in which you start with is up to you, I recommend at least 20-30 healthy and 5 sick.