Below is the first paragraph of Salinger's "The Ocean Full of Bowling Balls". I wonder what to turn things over his fingers means in this context? I imagine the little boy juggling things, but I don't have a clear scene in my mind (why would one need to roll forward to juggle?).
His shoes turned up. My mother used to tell my father that he was buying Kenneth’s shoes too large for him, or to please ask somebody if his feet were deformed. But I think his shoes turned up because he was always stopping on the grass, rolling his seventy-five or eighty pounds forward to look at things, to turn things over his fingers. Even his moccasins turned up.