For ages 9 to 12 years. Build a catapult that sends marshmallows flying. Make a perching parrot that balances on a high wire. Send a marble on a wild ride down your room-sized marble ramp. Yes, have a great time constructing more than 50 working science contraptions, using easy-to-find materials. Children will be building, questioning, creating, laughing -- and, learning -- as they explore the action-packed world of physics fun through science contraptions that really work. For children aged 7 to 14.