Give each group a stick of clay. Use cooperative brainstorming to consider the problem of boat design. Team then forms the boat. After 10 minutes, have them stop. One at a time the leader brings the group's boat to a tub of water and begins putting marbles in it until it sinks.
Recorder marks on a class chart the number of marbles the boat held.
When each team has finished, discuss the reasons for the different boat designs. Have students sketch the different boat designs and color in the number of marbles in each boat. Pass out craft sticks to each group. Take students to open field or wooded area. When the hunters find the object, they call a checker to verify the discovery.