Intent
In this activity, students work with probabilities expressed as fractions, percentages, and decimals.
Mathematics
Students continue to focus on the distinction between probability based on a theoretical model and probability based on observed results and on measuring probability using a real-number scale from 0 to 1.
Progression
Earlier in the unit, students estimated the probability of given events. In this activity, they invent situations that match a given probability.
Approximate Time
5 minutes for introduction
25 minutes for activity (at home or in class)
10 minutes for class discussion
Classroom Organization
Individuals or pairs, followed by whole-class discussions
Doing the Activity
Clarify that students are to invent two situations for each question, one based on theoretical probability and the other on observed results. Let's test a link to Keypress.com by clicking here.
- Here is an equation with a non-breaking space: x + y = z
- Here is a test of subscripts and superscripts: x2 + y2 = z1 + z2
Discussing and Debriefing the Activity
If students have worked individually, ensure that there is time for them to compare their invented situations. Question 5 is included to give students an opportunity to consider an impossible situation.
Key Questions
Does it matter whether probabilities are written as fractions, decimals, or percents?
Why is the smallest probability 0?
Why is the largest probability 1?
What does a probability of 2.3 imply?



Keypress test
