Both the grade 7+8 AND 9+10 students got started in Science class this year with a challenge. They had to design and construct a boat that could hold as many dry beans (or marbles) as possible without sinking. They could use a limited amount of aluminum foil and duct tape, along with other materials so groups had to make detailed plans before starting the construction. It was a fun activity for students to get to know each other and to review some math skills that they would be using in the course. The idea for this challenge came from the blog post, ‘Build a Boat (and a classroom culture)‘. The goal was to build a boat that cost the least amount per bean (or marble). All the materials were assigned set costs per unit and this added an extra level of consideration for each group. They may hold the most marbles, but was their boat most economical?
Each group had a very different design and some held up in the water much longer than others. It turns out that beans get soggy and wet when the boat sinks, so we had to substitute with marbles for later boats. Somehow we worked out the winner by total mass the boat could hold! It turned out the the largest canoe-shaped boat held significantly more marbles than the others and we ran out before the boat would sink! I had to do some adjustments with the calculations since a marble has the same mass as more than one dry bean. It all worked out well enough. Students summarized their findings by creating a whiteboard that illustrated their design, materials, measurements and total cost per bean or marble.