Lesson 2: What Actually Happens: Experimental Probability

About 30 minutes — Activity-based lesson

What You Will Learn

This lesson covers:

Experimental probability: calculated from actual experiment results
How to calculate: number of times it happened / total trials
Why experimental results rarely match theoretical exactly
Activity: flip a coin 50 times and calculate experimental probability of heads

Experimental probability: calculated from actual experiment results

This section covers the key ideas about experimental probability: calculated from actual experiment results. Discuss with your group or family and explore the concepts together.

How to calculate: number of times it happened / total trials

This section covers the key ideas about how to calculate: number of times it happened / total trials. Discuss with your group or family and explore the concepts together.

Why experimental results rarely match theoretical exactly

This section covers the key ideas about why experimental results rarely match theoretical exactly. Discuss with your group or family and explore the concepts together.

Activity: flip a coin 50 times and calculate experimental probability of heads

This section covers the key ideas about activity: flip a coin 50 times and calculate experimental probability of heads. Discuss with your group or family and explore the concepts together.

Check Your Understanding

1. What is experimental probability?

Answer: The probability you calculate from actual results. If you flip a coin 50 times and get 28 heads, the experimental probability of heads is 28/50 = 0.56 or 56%.

2. How is it different from theoretical?

Answer: Theoretical is calculated from math (50%). Experimental comes from actual results (maybe 56%). They are often different, especially with small numbers of trials.

3. Why do experimental results vary?

Answer: Because randomness means each individual trial is unpredictable. Just like weather — you know the pattern but not every specific day.

4. Is experimental probability wrong if it differs from theoretical?

Answer: No! Both are valid. Experimental probability is the reality of what happened. Theoretical probability is the mathematical expectation. They converge over many trials.

Key Takeaways

Experimental probability: calculated from actual experiment results
How to calculate: number of times it happened / total trials
Why experimental results rarely match theoretical exactly
Activity: flip a coin 50 times and calculate experimental probability of heads

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