The 3- and 4-year-old children are having trouble with the board game Trouble. The dice are just sitting there in a plastic bubble. “You have to do it like this,” their day-care teacher says as she deftly pushes on the plastic to make the dice flip. The children look at her as if she’s a miracle worker. During the day, Chelsea Lee helps one of her charges navigate a giggly game of hopscotch.