Teacher guidance

To help pupils understand the task, you might choose to introduce it with  a short video, with comments:

• Hilbre Island is a small island in the Dee estuary, near Liverpool. It is very important for the birds that migrate and nest there. People can only reach it by foot for a few hours a day, when the tide is out, so they must plan carefully when to walk across.

• You are given all the information you need to decide when to start your journey to Hilbre with friends; plan it to have as much time as possible to enjoy the island, but also make sure you can get back safely and do not get stuck there overnight!

The task requires calculations involving time.

During the task, the following probing questions may be helpful:

• What do you need to consider in making your choice? What are the key points?
• Are any of the three dates not possible? Why?
• Why have you chosen this date rather than one of the other dates?
• Will Jon and Lu understand your reasoning?

Further notes for teachers can be found in the Annex to the teacher guide.