A solar-powered Mars rover...
Reading while we are supposed to be eating breakfast... (How can I POSSIBLY tell him to put the book down?!)
And a really cool science demonstration.
This is actually a really great demonstration to show that molecules of a hot substance move quickly and molecules of a cold substance move slowly. Make identical glasses of ice water and really hot water. Put a drop of food coloring in each glass. In the glass of hot water the color disperses quickly while in the ice water it takes a long time.
We discussed what was going to happen before we did the experiment and Ben correctly predicted the outcome... but it looked way cooler than we expected.