Unit 8, Lesson 5
More Estimating Probabilities
Grade 7
Preparation
Lesson Narrative
In this lesson students compare the results from running actual trials of an experiment to the calculated expected probabilities. They also use their data to see that additional trials usually produce more accurate results as minor differences even out after many trials.
In the first activity, students spin four different spinners to see that the outcomes in a sample space may not be equally likely, and they examine the spinners to construct arguments (MP3) about why some outcomes are more likely than others. In the next activity, students draw blocks out of a bag repeatedly and use the relative frequency to estimate the probability of getting a green block (MP8).
- Describe (orally and in writing) reasons why the relative frequency from an experiment may not exactly match the actual probability of the event.
- Recognize that sometimes the outcomes in a sample space are not equally likely.
- Use the results from a repeated experiment to estimate the probability of an event, and justify (orally and in writing) the estimate.
Let’s estimate some probabilities.
Required Preparation
Each student will need a pencil and paper clip to use with the spinners.
For the digital version of the activity, acquire devices that can run the applet.
Prepare a paper bag containing 5 snap cubes (3 green and 2 of another matching color) for every 3–4 students.