This has been the topic of a number of threads on this site, and the fit between child and Montessori often comes down to a question of child personality, because the Montessori method calls for rigidity... students can work on whatever they want, but they must only use the educational materials in the prescribed ways, and follow instructions precisely. Any re-purposing of materials in fun or imaginative ways is strictly frowned upon.

For children with a preference for order and structure, it tends to be a great match. My child is a goofball, so that would have been a disaster.