dominoes, rolling marbles, racing balloon cars, object-launching catapults, and
whizzing zip-lines are all elements used to build Rube Goldberg machines in Crazy Contraptions. The book introduces
kids ages 9-12 (and beyond!) to the wacky machines designed by Goldberg, that
were based on complicated and ridiculous chain reactions to accomplish very
simple tasks. Then young engineers are invited to invent, design, create, and
play as they make their own Rube Goldberg machines.