Zahlenzorro - The Demand Book 4 Mathematics introduces favorite themes such as circus, fantasy, detectives, or pirates. The Zahlenzorro Demand Book 4 specifically includes more challenging tasks for further thinking and puzzling. All learning content for the fourth grade is covered, but consistently at an advanced level and without step-by-step instruction. It is suitable for independent learning, practicing, and continuing work - in school or at home in the afternoon. Self-explanatory and independent of any textbook, the Demand Book 4 motivates through the theme "Pirates and Ocean Worlds," which guides children throughout the entire book. The tasks are embedded in stories about pirates and treasures, islands, ships, whales, as well as marine researchers and divers. Accompanying them is the Zahlenzorro, who supports the students.