M4.6.2 For the adult
Relative frequency and expected results
A bottle top is dropped on a table. How can I find the chance that it lands top up?
What this chapter teaches
When outcomes are not equally likely, the probability is estimated from an experiment: relative frequency = times it happened ÷ trials. More trials usually give a better estimate, but never a proof. The expected number is probability × trials, and it is an average, not a promise.
Three questions to ask
There is no one right wording. Listen for the idea.
- How would you estimate the chance that a bottle top lands top up?
- Why do 500 drops give a better estimate than 10 drops?
- If a fair coin is tossed 200 times, why might you not get exactly 100 heads?
After the chapter, the learner can
- Estimate a probability from the results of an experiment
- Find how many times to expect an outcome in 200 tries
What they copy into their notebook
Relative frequency = times it happened ÷ trials. It estimates a probability, and more trials usually improve it. Expected number = probability × trials, an average and not a promise.