One advantage is that he doesn't forget details.He knows each child 's name,the parents'names,and what each child knows and needs to know.In addition,he knows each child's pets and hobbies.Mr.leachim does not make mistakes.Each child tells Mr. leachim his or her name and then enters an identification number.His computer brain puts the child 's voice and number together.He identifies the child with no mistakes.Then he starts the lesson.