Sixth-grader Rufus Mayflower doesn't set out to become a millionaire. He just wants to save on toothpaste. Betting he can make a gallon of his own for the same price as one tube from the store, Rufus develops a step-by-step production plan with help from his good friend Kate MacKinstrey. By the time he reaches the eighth grade, Rufus makes more than a gallon -- he makes a million! This fun, breezy story set in 1960s Cleveland, Ohio contains many real-life mathematical problems which the characters must solve to succeed in their budding business. Includes black-and-white illustrations by Jan Palmer. This 35th anniversary edition includes an exclusive author interview and reader's guide with book summary and discussion questions.