Chance and Experimental Probability
Year 5 students conduct chance experiments, record results, and compare experimental probability with theoretical probability using fractions and percentages.
What You Need to Know
Key Concept Diagram
Theoretical probability is based on equally likely outcomes: P(event) = favourable outcomes ÷ total outcomes
Experimental probability comes from actual trials and may differ from theoretical probability
More trials generally bring experimental probability closer to theoretical probability
Probability is expressed as a fraction, decimal, or percentage between 0 and 1 (or 0% and 100%)
Key Vocabulary
Probability
A measure of how likely an event is, from 0 (impossible) to 1 (certain)
Theoretical probability
The expected probability based on all equally likely outcomes
Experimental probability
The probability calculated from actual results of repeated trials
Trial
One single test or experiment performed to collect data
Knowledge Check
Select the correct answer for each question. Click "Check Answer" to see if you are right.
Question 1
A bag has 3 red and 7 blue marbles. What is the theoretical probability of picking a red marble?
Question 2
A coin is flipped 40 times and lands heads 18 times. What is the experimental probability of heads?
Question 3
The theoretical probability of rolling a 6 on a fair die is 1/6. If you roll 60 times, about how many sixes would you expect?
Key Concepts Summary
- ●Theoretical probability is based on equally likely outcomes: P(event) = favourable outcomes ÷ total outcomes
- ●Experimental probability comes from actual trials and may differ from theoretical probability
- ●More trials generally bring experimental probability closer to theoretical probability
- ●Probability is expressed as a fraction, decimal, or percentage between 0 and 1 (or 0% and 100%)