Oakland Terrace Math Work Grade 5

In this lesson, students explore the difference between the theoretical probability (what should happen) and the experimental probability (what does happen) when experimenting on a fair spinner.

This lesson uses the following website:
http://nlvm.usu.edu/en/nav/vm1

Students express the theoretical probability of landing on each color of the spinner they find on the website. The probability is expressed either as a fraction or as a ratio.

Students see immediately that the spinner is fair the way it appears initially.

Students record the results of their spins. They should notice that the results become closer to the theoretical probability the more they spin (in this example, after 50 spins, the results for each color is closer to the theoretical probability of 1/5 for each color than after just 10 spins).

This student has a clear understanding that the theoretical probability does not necessarily match what happens in the real world.

By finding the mean of the data for the experimental probability, students start to see the connection between experimental and theoretical. As this student explains, only one of the colors matched the theoretical probability of 10 out of 50 spins. But when the students consider the other colors, some exceeded the theoretical of 10, and others fell short. No longer is it a mystery that the experimental and the theoretical do not match. It helps to explain that although a spinner might be fair, you are not assured of the same results.

Indicators:
5.5.2.1 use a fraction or a ratio to describe the probability of an event.

4.5.4.3 compute and compare range, mean, median, and mode of data sets.

5.6.3.1 predict the probability of a simple event based on the outcomes of
an actual event or experiment and compare the results to the theoretical probability of the event.

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