Cosy Corner

Why do this problem?

This problem offers an opportunity to explore and discuss two types of probability: experimental and theoretical. The simulation generates lots of experimental data quickly, freeing time to focus on predictions, analysis and justifications.

Possible approach

Demonstrate the interactivity a few times, explaining that to win, at least one corner needs to contain a red ball.
Invite students to estimate the probability of winning. Allow students some thinking and discussion time in pairs before bringing them together to state their initial conjectures.
Students may find this Recording Sheet useful, to work out the different possible outcomes.
Record their conjectures on the board and then run the interactivity a few hundred times. Then revisit students' conjectures and discuss which ones matched the experimental data, before rounding the activity off by discussing which methods for recording the different combinations were both successful and efficient.

Key questions

Are there efficient systems for recording the different possible combinations?
What counts as a different outcome?
If the red balls are in the same position but a blue and yellow ball swap places, does that count as a different outcome?

Possible support

An alternative problem for exploring theoretical and experimental probability is Flippin' Discs

Possible extension

A follow-up problem could be Two's Company

Teachers may want to use this recording tool to gather the results of other similar experiments that their students are carrying out: