In the Land of Unlearned Lessons (V Strane Nevyuchennykh Urokov)

The story's hero, Vitya Perestukin, a fourth-grade student, a failure, and a slacker who hated doing his homework, experienced a magical event—he found himself, quite miraculously, in the Land of Unlearned Lessons. And here the boy had to confront the mistakes he'd made while hastily preparing his homework. What could Vitya do? Correct his mistakes, of course! Otherwise, he'd never return from this magical land...