Have you heard of a series called “The Land of Stories”? It is a great series, by Chris Colfer, and it has over 400 pages. To me, it’s for Gr.5 and up books, even though I already started reading them when I was Gr.4.
The first book in the series is called The Wishing Spell, and I think it’s the best book in the series. I encourage you to read it.