The Preschool Wars

Zaire Hines is standing in front of a pint-size table, building a castle out of red and blue plastic cups. He stacks them into a tower and then, in his excitement ("Look what I did!"), accidentally knocks them to the floor. If he were at day care or in his bedroom, Zaire, 4, might have shrugged and moved on to another set of toys. But he's at Project Enlightenment, a publicly funded preschool in Raleigh, N.C., where his teacher, Kim Jackson, is using the cups to help Zaire work on counting and other premath skills as well as underlying ones like...