by H. B. Farmer
Disorder reigns in Digitopolis! Something has gone haywire in the the land where numbers rule. Milo, Tock, and the Humbug must return to Digitopolis to restore order to the realm. Their journey begins with a visit to their old friend the Mathemagician, who sends them on their quest. During their adventure they meet a cast of odd characters and encounter some challenging mathematics.