Design a tool.
This can be something that already exists in the tool world, or it can be an invented tool for a particular job that you have in mind. This can be very simple or extremely complex, it's up to you. Maybe even think about some of the first tools ever invented by man or animal to serve them.
Here is the definition of the word tool:
1. an implement, esp. one held in a hand, as a hammer, saw, or file, for performing or facilitating mechanical operations.
2. any instrument of manual operation.
3. the cutting or machining part of a lathe, planner, drill, or similar machine.
4. the machine itself, a machine tool.
5. anything used as a means of accomplishing a task or purpose: Education is a tool for success.
6. a person manipulated by another for the latter's own end; cat's-paw.
7. a means to an end, (a book cover can be a marketing tool).
As you can see, lots of meanings, open for interpretation by the creator. Have fun, only play along if you are inspired by the challenge.
Here are the design solution other kids from around the world made in response to this challenge.