Floating Pumpkin

At the School of Wonders, we believe that children learn best through experience. As a result, academic lessons are purposely structured to appeal not only to the children’s intellect and curiosity, but to engage their senses as well.


As our Fall Festival is approaching, each child brought in a pumpkin to decorate and display as part of the pumpkin patch.

However, before painting the pumpkins, the teachers decided to use the pumpkins as a way of introducing the children to a range of elementary physics terms.


The children carried their pumpkins outside to the backyard garden, where transparent plastic tubs filled with water were waiting.

Lab report templates were provided, and the students went straight to work recording their hypothesis and reasoning, along with the weight and size of their pumpkin. In recording the data, they utilized two different units of measurement and were asked to articulate the utility of each. They also revisited a term they learned in Math Lab last semester, circumference, or the linear distance around a curved object. The students created a chart to display everyone’s data, so they could refer to the weight and size of each pumpkin before it was dropped and as a class predict whether it would sink or float.


The students’ hypothesis mostly indicated that their pumpkin would sink, and the reasons listed usually predicted that it would because of it’s weight. However, a few students believed their pumpkin might float.

One student’s hypothesis did not focus on his pumpkin, but rather the water surrounding it. His lab report stated that he was certain that the weight of the pumpkin would cause the level of the water to change. As teachers, we could not have been more excited to see that his hypothesis anticipates the Archimedes’ principle, which indicates that, “the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces.”

Finally, it was time to sink the pumpkins! The pre-kinder class and kindergarteners joined our older students for this exciting experiment. Before the first pumpkin was dropped in, the teacher asked the students whether they believed it would sink or float. An overwhelming response of, “Sink!” came from the crowd. After a huge splash, and much to the students surprise, the pumpkin floated!


As we went through everyone’s pumpkins, the students observed that every single pumpkin floated, despite it’s weight or size. They were astonished!

The group moved into a meeting when the experiment ended. They shared their observations, recapped the terms they’d practiced measuring. Then, their reflection went further. They started to offer assessments of why the surprising results were so uniform. One student stated that the reason every pumpkin floated was related to the fact that they all had air inside – enough air to keep them above water despite their weight. Another student shared his theory that the force the pumpkin as exerting downward on the water was not as strong as the force the water was exerting upward on the pumpkin, so it stayed afloat. Perceptibly, this theory triggered a light bulb moment for other students, who were suddenly wide-eyed in exchanging their thoughts about the “forces” of the pumpkins and water.


As teachers, we were so pleased to see how the students seized the opportunity to penetrate deeply into their observations from the experiment to approach rules about the relationships that govern the physical world. In several ways, their reflection surpassed the span of concepts suggested by elementary physics objectives, and the dialogue came solely from the students.

The pumpkin floating experiment was a classic demonstration of the element of play we factor into every lesson at the School of Wonders. It was also a classic demonstration of the trust we place in our students, who, when presented with grade-level appropriate educational objectives, always elevate the learning to topics and questions academically required of students far beyond their age level but perfectly appropriate for their voracious curiosity and capacity to know.

Research is formalized curiosity.
Zora Neale Hurston

This entry was posted in Elementary. Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *