Splitting the pumpkin

Kindergarten green group did some seasonal math and science last week.

 

A battery of tests was carefully planned.

 

Predictions were made.

 

The sequence mattered, too; the buoyancy tests, for instance, needed to happen before the pumpkins were opened up and de-seeded.

 

Along the way, the students picked up some vocabulary: estimation, tally, and, especially, circumference.

 

Yesterday, eighth graders were talking pumpkin circumference, too.

 

The topic was the power, and limitations, of the scatter plot graph.

 

Students across the US had wrapped rubber bands around pumpkins until the pumpkins collapsed.

 

Then, they plotted the number of rubber bands used, and the circumference of their pumpkins, on a shared graph.

 

The result was a very messy scatter plot graph.

 

Students derived a rough formula for the trendline, and used it to predict how many rubber bands would collapse their pumpkin: one hundred and ninety-five.

 

Then, they went outside to test their prediction.

 

Well trained scientists, they tried to limit the number of variables.

 

They held the pumpkin from the bottom, for instance, and did everything they could to avoid adding pressure to the sides.

 

Everything, that is, except adding rubber bands, five at a time, to the pumpkin's circumference.

 

As the count blew past two hundred, the tension mounted.

 

At three-fifty, things got quiet.

 

At three hundred and ninety, the adult filming the pumpkin unaccountably chose to stop filming and missed the moment of truth.
 

 

The pumpkin did not exactly explode so much as it was sliced.

 

Back in the classroom, the students debriefed.

 

There were many variables that could have accounted for the huge gap between their prediction and their result.

 

The type of rubber band. The thickness of the pumpkin. The angle of the rubber bands. Any number of things.

 

Yet, when they checked the graph, they saw that their result was well within the big cloud of results.

 

The lesson on scatter plot graphs, then? They'll reveal a general pattern, but they're not precise.

 

The other lesson? Yes, it is possible to destroy a pumpkin using only rubber bands.