by Dan Meyer

• 1. How deep is the chasm?
• 2. Guess as close as you can.
• 3. Give an answer you know is too high.
• 4. Give an answer you know is too low.

• video — the team tosses a rock into the chasm

• 5. What information will you need to know to solve the problem?

• video — a timer tracks the rock as it falls

• 6. If you drop a rock off the top of the Golden Gate Bridge, how long will it take you to hear a splash?
• 7. Falling Glowsticks.