Set in 1960's Cleveland, Ohio, follow 6th-grader Rufus Mayflower as he and his friends use real-life mathematical problems to help their budding business making toothpaste succeed.
It's Duncan's birthday, and all the Crayons want to make him a card! With their fun and quirky illustrations of firetrucks, dragons, and (dare we say?) wheat, these creative Crayons each have something different to contribute. When they come together, they can make something truly spectacular to celebrate Duncan's birthday!