The revised edition of "Thinking and Calculating" is designed to equally promote process-related and content-related mathematical competencies. To enable children to learn and succeed as independently as possible, "Thinking and Calculating" includes recurring task formats. In this way, children can tackle or discover new, challenging, and problem-oriented questions using familiar formats. Planning, testing, evaluating, and discarding calculation and solution methods are integral to the mathematical learning process for children. Therefore, "Thinking and Calculating" increasingly encourages and fosters self-directed problem-solving approaches and engagement with them, for example, in calculation conferences. Many tasks are designed to facilitate partner or group work, thereby creating additional communication opportunities and promoting independence and self-organization.