The first-grade students at Chatterton Elementary School in Merrick performed some experiments on pumpkins during class Tuesday.

The young scientists measured the lines in a pumpkin, its density, volume and mass.

"It's all about predicting, estimating and experimenting," said teacher Jamie Feltman. "We talked about how a scientist first makes an estimate, they experiment, they have a hypothesis and then take the actual measurement of the pumpkin."

After gathering all of the info, students put the pumpkins in a barrel filled with water to see if they would float.

None of the students were able to guess why their pumpkins didn't sink.

The reason? Air was inside of the pumpkins - and air is lighter than water.