### Why do this problem?

Probability is a difficult concept and questions such as this, which invites discussion, can help children to get to grips with the difference between a calculated result (theoretical probability) and what actually happens (experimental probability). Playing the game with a bag full of coloured balls can help to make the link.

### Key questions

The first ball taken out is a red one, how many balls of each colour are left?
What is the chance of picking another red ball?
What is the chance of of picking a yellow ball?
If you had won some money and could lose it by playing again, would you stop playing? Why?

### Possible extension

Make up a similar question with different numbers of coloured balls. Are there any combinations of colours that would make it clear what to do? Why?

### Possible support

Playing the game with a bag full of coloured balls and discussing the possible outcomes can help to make the link. Talk is really important in understanding probability.