This problem offers children the opportunity for children to get a feel for experimental probability and to work systematically to find all possible outcomes.
The interactivity will help children to get a feel for this problem. However they should be encouraged not only to identify a pattern in the data they collect, but also to explain why this pattern occurs.
The problem builds on the ideas of fairness introduced in Domino Pick and would benefit from discussion.
Of course this problem could also be tackled practically. Pupils themselves may throw the balls outside and collect data for the whole class.
Why not find three balls so that you can try playing the game with a friend. What happens?
Is it important that there is only red ball but two blue balls?
How could you record what you have found out?
Would it be helpful to use some red and blue counters for working out the different possibilities?
Learners could try Tricky Track once they have had a go at this task.
Suggest trying with real balls first. Some red and blue counters might be helpful for working out the different possibilities.