Mathematics — Probability · Marble probability experiment

Marbles Probability

Use the visible red, blue and yellow marble counts to distinguish counts of favourable outcomes from total outcomes.

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📝 Description

Marbles Probability is a visual probability game based on marbles and outcome prediction. It helps learners practice likelihood, counting favorable outcomes, and interpreting probability questions.

📋 Instructions

Study the marbles shown and answer each probability question carefully. Use counting and comparison to select the correct answer.

🎓 Learning Guide: Marbles Probability

Learning focus: Use the visible red, blue and yellow marble counts to distinguish counts of favourable outcomes from total outcomes.

Mathematics — Probability Marble probability experiment

Learning objectives

Count the marbles in each colour category
Express a simple colour probability as a fraction
Check whether a changed jar composition changes the predicted chance

Concepts and principles

For a uniformly random draw, P(red)=number of red marbles / total marbles.
Probabilities of mutually exclusive colours add to 1 when every marble has exactly one of those colours.
A theoretical probability is not guaranteed to match the frequency observed in a small set of random draws.

Examples and worked solutions

Independent teaching example (not verified as an in-game prompt): A jar contains 3 red, 2 blue and 5 yellow marbles. What is P(blue)?: Worked solution: There are 10 marbles in total and 2 are blue, giving 2/10=1/5=20%.

Guided practice

Read the colour counters and calculate the total before answering a question
Write a predicted fraction for the colour mentioned by the prompt
If multiple jars/rounds are available, compare how a new composition changes the probability

Expected observations and explanations

Changing a colour count changes both the favourable count and usually the total.
A probability of 0 means no favourable marble; 1 means all marbles are favourable.

Assessment questions and answers

If a jar has 4 red and 6 blue marbles, what is P(red)?: Answer: 4/10=2/5.
Why should all visible colour counts be added?: Answer: Any possible selected marble belongs to the total sample space, so the denominator counts all marbles.