Puzzle games aren't just something you play on consoles, computers and smartphones. They're also something you can play with a chocolate bar.
Next time you're hanging out with your friends, invite them to take the Infinite Chocolate Bar Challenge: try to remove one rectangle or square from a bar of chocolate, and end up with a bar that looks like nothing's missing.
I've seen it work on delicious, segmented chocolate of various sizes, but it definitely works on a regular old Hershey's bar. For the math-oriented among us, here's a more geometric explanation of the solution: