By Mary Wiltenburg.  This article originally appeared in The Christian Science Monitor, February 10, 2009 Some of her kids can multiply dozens; some are still adding on their fingers. Some, by Georgia standards, are failing third grade math. But today, whatever Ann Griffith’s students know about division, they’re fired up about it. A dozen 8-to-10-year-olds sit cross-legged on the carpet of her trailer classroom, around … Continue reading Third-grade math: a teacher’s calculus