4-story Towers

After finising up a math test in class, I posed the tower question to my group of fourth graders. I asked the students to predict how many four-story towers could be built using fifty of each of two colors of connecting cubes. Students recorded their predicitons on a lab sheet. Once the predictions were recorded, I instructed them to use the connecting cubes to build as many uniques four story towers as possible. As I walked around to see what the students were doing to solve this problems I witnessed many different things. Two groups split the towers of ten into towers of four of all the same color and one group seperated every cube and spread them out all over the desks. Another group I observed made two 4-story towers of the same color and then made 3-story one color towers and added the other colors to make the fourth story. They continued to take away the first color until they felt they had none left to change. The last group had over twenty towers, that of course were all the same color. I directed the students attention to the Promethean Board and revisited the original task. I reminded them that the towers needed to all be different. At that time the groups who were building many towers realized what was happening and started to pair up the towers they had built.
At the end of the lesson I asked each group how many towers they had. Many of the groups had 16 towers. Students recorded their towers onto the lab sheet and were given an opportunity to write why they think there were only 16 possible tower combinations. Students were very engaged and excited and asked if we could figure out how many towers they could build that are 5-stories tall. I assured them that we would continue the investigation this week in math centers.