This is one of those rare books that actually delivers on its promise: making math feel like an adventure rather than a chore. Hans Magnus Enzensberger uses dream logic and a quirky mentor character to introduce genuinely sophisticated concepts—primes, Fibonacci, Pascal's triangle—in ways that build intuition rather than just memorization.

The imaginative framing works. Robert's twelve dreams feel like Alice in Wonderland for number theory, and the Number Devil himself is cheeky without being obnoxious. Multiple kid reviews confirm this book makes math 'click' for reluctant learners, which is no small feat.

The translation from German occasionally shows (some phrasing feels slightly off), and the 'devil' name might give pause to some families, though he's more mischievous than sinister. But those are minor quibbles for a book that genuinely enriches how kids think about patterns and numbers.

If your kid groans at math homework or you want to spark curiosity beyond the worksheet grind, this is a solid pick. It's not a page-turner in the Harry Potter sense, but for what it is—a mathematical adventure that respects young readers' intelligence—it's excellent.