keni

A cartoon boy in a green shirt stands in a classroom, then the scene cuts to a close-up of a boy's face in front of a chalkboard with math problems, followed by a shot of three boys at desks, one with a thoughtful expression, another smiling with hands behind his head, and a final shot of the boy in the green shirt standing before a chalkboard with "today's topic" and the letter "D" written on it.