Second grade students have been learning about the properties of matter in science. Recently, they used their growing understanding of solids, liquids, and gases to design boats out of aluminum foil. Students experimented with different sizes and shapes as they tried to design a boat that could hold the most weight without sinking.

Students were given a square of aluminum foil to build their boat with a partner. As a class, they analyzed the properties of the foil to understand how the material might affect the construction process. Students noted that aluminum foil is metallic, thin, lightweight, flexible, easy to rip, and therefore fragile. While imagining boats with sails, ladders, or smokestacks was tempting, students were cautioned against making their designs too elaborate. Instead, Design Teacher Deborah Morrone Bianco asked students to focus on the relationship between the shape of the boat and how much weight it can carry.

Students sketched out their first design and molded their boats to match. Then, they made predictions about how many objects their boats would hold. The first designs for many teams were small and dense, with many layers of foil compacted together. However, when they tested those designs in the water, students saw that the denser boats sank faster when weight was added as they displaced the most water. As other teams tested their designs, students noticed that the more successful boats were less dense, had a greater surface area that allowed the weight to be distributed and had deeper sides to prevent displaced water from filling the boat. Teachers encouraged students to observe the forces of buoyancy and gravity on each design. Before creating a second design, students reflected in writing on the flaws and strengths of their first attempt and documented what they planned to change to improve their second design. They also observed what worked or didn’t in their classmates’ designs to see if there were ideas that they could incorporate. Most designs improved significantly on the second attempt, with one raft-style boat holding over 100 pennies without sinking!