Students learn how to calculate both theoretical and experimental probability by rotating through
a series of work stations.
Upon completion of this lesson, students will:
be able to calculate both experimental and theoretical probabilities
display probabilities in both graphical and fraction form
Technological: Students must be able to:
use a browser experimenting with the activities.
enough stations so that each pair of students can be working at an individual station. (You
may want to have multiples of each station because some stations take longer to complete than
2 race boards and 4 race cars
2 pieces of paper numbered 1- 12
10 square pieces of paper or 10 poker chips
an opaque bag
15 white marbles
5 red marbles
3 index cards (a mole drawn on the reverse of one card)
a deck of playing cards
access to a browser
The chances of something happening, based on repeated testing and observing results. It is the ratio of the number of times an event occurred to the number of times tested. For example, to find the experimental probability of winning a game, one must play the game many times, then divide the number of games won by the total number of games played
Any one of the possible results of an experiment
The chances of events happening as determined by calculating results that would occur under ideal circumstances. For example, the theoretical probability of rolling a 4 on a four-sided die is 1/4 or 25%, because there is one chance in four to roll a 4, and under ideal circumstances one out of every four rolls would be a 4. Contrast with experimental probability
Focus and Review
Introduce the idea of probability through a discussion that they can relate to. Students may be
familiar with winning prizes through cereal boxes or soda cans for instance. Students will be able
to calculate both experimental and theoretical probabilities as well as display probabilities in
both graphical and fraction form.
Let the students know what they will be learning and doing today. Say something like this:
Today we are going to explore probability with a number of different activities.
We will be moving around the classroom and using the computer today, but for now I would like
you to remain in your seat with the computer off or closed until I give you further
Work through an example work station with the students.
Fill out the appropriate section on the with the class.
Explain the procedures to be followed at each station:
Write whether you think the coin is more likely to land on heads or tails and why.
Calculate the theoretical probability.
There should be 2 pennies at the station. Each person should flip the penny and record the
number of times it lands on heads and the number of times it lands on tails.
Make a graph representing the results you obtained from the penny flip.
Have each group share the experimental data they collected from one experiment. Ask them if
the experimental probability they calculated is the same as the theoretical probability.
Reinforce the concepts of theoretical verses experimental probability.
Compile the class' data for all the experiments and compare the individual group experimental
results to the collective class results. The compiled class results should be closer to the
theoretical probability than most individual group's results.
Discuss why this is so.
Discuss why computers might be helpful when working with probability experiments.