The Math Elves come from the student competition organized by the German Mathematical Society (DMV), known as "Math in Advent." For this book, the most beautiful problems from recent years have been selected and thoroughly revised. They provide a humorous insight into the wonderful diversity of mathematics, promote mathematical curiosity, and encourage creative thinking in a playful way. In doing so, they expand the school-taught image of mathematics and inspire even those who have previously struggled with the subject. The second edition includes additional current problems from "Math in Advent," expanded solution texts, new problems for further exploration, and additional tips for teachers on how to use it in schools or teacher training. Suitable for students from elementary school (especially grades 4 to 6), parents, and mathematics teachers.