Science took a competitive turn as Grade 6 students studied density by exploring what makes a boat float during the STEM Build-a-Boat Challenge. 

“The competition presents a conceptual and fun way for students to explore density,” said science teacher Lindsay Chiodi. “We're currently in an introduction to chemistry unit, and density is a major concept as it is a physical property of matter and can be used to identify matter.” 

Students worked in teams designing and building boats capable of supporting as much mass as possible without sinking. For a boat to float, it must have less density than water. The incremental addition of metal washers tested students’ designs. 

Material budget heightened the challenge. Students needed to be cost-conscious as they built their vessels, working with a fictional price sheet to calculate the total cost of their design.

“Ultimately, a cost-efficient boat that can support a lot of mass will win,” said Chiodi. “The project offers students a way to apply math in science as they practice volume measurements, find the mass, and then ultimately calculate density. In general, it's a way to make sense of objects, liquids, and substances while they explore the answer to the question of why certain things sink versus float.” 

Taking inspiration from bamboo boats, Lucas Ippolito ’29 and Cole Madan ’29 creatively thought of ways to modify materials to reduce their spending. Pointing to the base of their cardboard platform Lucas noted, “we used two straws, but we cut them up.”

The Build-a-Boat Challenge culminated in weeks-long work, including density labs, homework, and classwork exploring volume, mass, and density measurements. 

“With this competition, they are pulling all that knowledge together,” said Chiodi. “We also did a unit within this to cover some properties of water, including buoyancy, displacement, adhesion, cohesion, and surface tension.”

Following the exciting competition, students reflected on their strategy and what changes they might make to improve their designs. Many students felt they had been too frugal in their decisions and would have purchased additional materials. 

Emily McGuire ’29 wrote that she would use more foil to “make a higher base, so it can be above the water, and put more straws at the bottom.”

Winners in each class received awards from Chiodi. The grand prize was a dress-down day, which Sylvie Grabowski '29, Elias Boben '29, and Henry Perkins '29 won. Their boat, which they named Floater, held a staggering 89 washers.