The carpeted room is full of children in skullcaps crouched on prayer mats, reciting verses from a holy text. Some mumble the words under their breath; others sing them out. They rock back and forth as they chant, their disparate voices blending into an ethereal melody. The children, ages 7 to 14, are full-time students, in class 8 a.m. to 5 p.m., Monday through Friday, even in the summer. But they are not studying math, science or English. Instead, they are memorizing all 6,200 verses in the Koran, a task that usually takes two to three years. It would hardly...