Unit 8, Lesson 1
Mystery Bags
Grade 7
Preparation
Lesson Narrative
To introduce the unit on probability, students play a game to collect data about what is inside bags and then decide which bag is most likely to give a desired result. The process of using previous results from repeated trials to inform the likelihood of future events is one way to estimate probabilities that will be revisited later (MP8).
Bags that contain a certain number of colored objects will be used in this unit. To reuse materials already in the classroom, colored snap cubes are recommended, but any items of different colors that cannot be determined by touch will work. If there are not enough suitable items, equal sized pieces of paper can be colored or have the color written on them and used in the bags.
- Compare outcomes for different experiments, predict which experiment is more likely to produce a desired result, and justify (orally and in writing) the prediction.
- Describe (orally) how we can use the outcomes from previous experiments to help determine the relative likelihood of future events.
Let's make predictions based on what we know.
Required Materials
Activity 2
Required Preparation
Prepare enough bags of blocks so that each group of 4 students can have one bag and all groups will have had a turn with each color of bag after three rounds.
- Label one-third of the bags "green" and put 9 green blocks and 3 blocks of another color into each of these bags.
- Label one-third of the bags "blue" and put 8 blue blocks and 8 blocks of another color into each of these bags.
- Label one-third of the bags "red" and put 4 red blocks and 10 blocks of another color into each of these bags.