Implementing the Professional Standards for Teaching Mathematics: Teaching and Learning Mathematics through Classroom Discussion

Tien-Tien announced during the news of the day that her grandmother was coming for a visit. Her third-grade teacher later used this news to introduce the mathematics lesson as follows: ‘If Tien-Tien's grandmother leaves China tomorrow morning, how long do you think it will take her to arrive in North Carolina?” The discussion that followed included a variety of important questions and comments. “Is she going to fly or take a boat?” “How fast does a plane fly?” “Will she come this way (pointing to Europe on the map) or that way (Pacific Ocean)?” “Can she sleep on the plane or will she need to land someplace so she can sleep in a bed?” “Where can the plane land on the way here from China?” “How often does a plane need to land for gas?” “I know that my cousin in Chicago is one hour later than we are. If she has to land in Chicago. won't that make a difference in how we figure the time?”