**Alternative prompt **

**P(2 heads and 2 tails) when you flip 4 coins = **

**2 x P(1 head and 1 tail) when you flip 2 coins**** **

This prompt was devised by **Nicola Stokes** (a Head of Mathematics in East Sussex, UK). Nicola tried it out with her year 9 class. The students responded to the prompt by asking the questions and making the statements above. Nicola reports that the prompt "worked really nicely and all of the class chose to continue to investigate if the prompt was true as they couldn't immediately see that it wasn't." During the inquiry, the students developed fluency in constructing sample space diagrams and tree diagrams.