Goal: Predict if something is possible, then find out
Grades: K, 1, 2, 3, 4, 5, 6, 7 Group size: Any Time: 10 to 20 minutes
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Materials: Paper and pencil (optional) Prerequisites: None |
Decide on a claim that involves measurement. Children will predict whether the claim is possible.
For less challenge, choose something that a group can easily test out. For instance:
- If we joined hands, we could circle the tree.
- If we lay down head-to-foot, we’d span the basketball court.
For more challenge, choose something that children can’t easily test out. They’ll need to estimate:
- If we stood on one anothers’ shoulders we could reach the top of the building.
- If the entire afterschool program joined hands, we coul reach around the block.
Tell everyone the claim. Ask those who think it’s possible to raise their hands. Then get a show of hands from those who think it’s impossible. Encourage children to explain their thinking
2. Try it or estimate
Children test out the claim or they reason about the answer. For instance, if the question involves height when standing on one another’s shoulders, they estimate the height to one person’s shoulders and multiply by the total number of people.
Variations
Compare Groups (Grades 3, 4, 5, 6, 7)
If it’s not possible for your group, would it be possible for a different group? A group of younger children? A group of athletes? Try it, or use reference books to make a prediction.
Hundreds and Hundreds (Grades 3, 4)
Ask the group to brainstorm some possible/impossible statements that involve the number 100, such as “All of us together have more than 100 siblings.” Then, children figure out if the statements are possible.
Ask the group to brainstorm a few statements that involve the number 1,000, such as “All of us together have more than 1,000 CDs.” Then, children figure out if the statements are possible.
Books and Other Resources
Book ideas to come!
Probability
The probability of an event is the chance that it will happen. Children need to learn to distinguish between what’s possible—what could happen even if it never does—and what’s impossible.
Is
it possible that four children holding hands could reach all the way around
the block? How do you know?
Investigating this involves drawing on observations, commonsense knowledge, and mental math: If a typical 12-year-old has a 5-foot arm span, four kids together would only reach about 20 feet. Even allowing for very long arms, they’d never reach around the block.
Connections
Evaluating claims about likelihood
Probability can influence small and large events in our lives. A 75% chance of light rain means it is probably going to rain, but the worst that can happen is that you get wet. A 75% chance of a major hurricane means that a horrible storm is likely—but not certain; if you don’t or can’t evacuate, you might be in danger.
In court, lawyers and jurors reason about what is possible, making decisions that can change lives. They can’t always verify claims, but they need to imagine what could have happened and what would be impossible, given all the evidence.
©2008 TERC, Cambridge, MA. All rights reserved.
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