Book excerpt: Motivate your students to break out of their "fog" and focus on problem solving and learning with these 30 difficult-level brainteasers. They are perfect for students whose critical-thinking skills have come a long way and who need a challenge. The packet includes a variety problems from riddles to math problems. Each BrainStarter requires very little time and no setup, making them easy to incorporate into your daily plans. You can also try them with the entire class or as quick team-building exercises.