Unit 8, Lesson 4
Estimating Probabilities through Repeated Experiments
Grade 7
Preparation
Lesson Narrative
In this lesson students roll a number cube many times and calculate the cumulative fraction of the trials for which an event occurs to see that in the long run this relative frequency approaches the probability of the event. Students must examine the structure of the repeated trials to recognize the connection between long-run frequency and probability (MP8). They also see that the relative frequency of a chance event will not usually exactly match the actual probability. For example, when flipping a coin 100 times, the coin may land showing a head 46 times instead of exactly 50 times and not be considered unreasonable.
- Describe (orally and in writing) patterns observed on a table or graph that show the relative frequency for a repeated experiment.
- Generalize (orally) that the cumulative relative frequency approaches the probability of the event as an experiment is repeated many times.
- Generate possible results that would or would not be surprising for a repeated experiment, and justify (orally) the reasoning.
Let’s do some experimenting.
Required Materials
Activity 2
Required Preparation
Requires 1 number cube for every 3 students. Access to graph paper may be useful, but is not required.
For the digital version of the activity, acquire devices that can run the applet.