My five-year-old grandson, a major dinosaur fan, is thrilled with this. It allows him to feel like a real paleontologist; the child has to work in an exacting manner. The excitement builds as something becomes visible. I estimate it will take about four half hour sessions to excavate the little dinosaur within. Suggestion: Hide the box, or mask the area that details which dinosaur is encased. Part of the fun lies in wondering what’s within! A great little find, very reasonably priced.