Design a Floating Cork Boat
Kids love experimenting to see what sinks and what floats. And aside from being fun, this kind of hands-on exploration is great practice in the scientific method, not to mention a cool introduction to physics.
Here's a great activity that uses corks and toothpicks to create a fleet of floating boats. Which design makes for the most seaworthy vessel? Your child will need to use creative thinking and experimentation to find out!