One Potato, Two Potato, Three Potato, Four

by Michael Porter
The fifth graders have been studying electricity and how to assemble electric circuits in science class, but Fifth and Sixth Grade Teacher Dona Kenny had one last — and very cool — experiment for them.
"As a fun culminating activity, we decided to see if we could power a small LED light bulb using only potatoes as the energy source," said Ms. Kenny.
The students had previously studied parallel and series circuits, and they had to decide what kind of circuit would work for this experiment. To create the "battery" the student inserted a copper penny and a galvanized (zinc plated) screw into opposite sides of a potato.

"You put the penny in the potato and then you screw the screw in the potato," explained 5th grader Gia E. "You clip an alligator clip to each of them and then clip it to the light bulb."
The students discovered that sometimes one potato doesn't produce enough power, so they added more potatoes to their circuit.
"If it didn't work you have to keep adding potatoes until you got it," Gia said.
Depending on the size of the potato, the students were able to light the LED bulb with either three or four potatoes.
"They wanted to know if the light would shine brighter if more potatoes were added to the circuit, so they were encouraged to give it a try," said Ms. Kenny. "The light did indeed burn brighter with more potato power!"

Fifth grader Neil S. now understands the concepts.
"The potato juice inside the potatoes has a little bit of electricity in the chemicals," said Neil. "I at first did not think it would work, and then it actually worked and I was very shocked!"
Using hands-on experiments really helps the students to produce core memories.
"I thought it was kinda wierd that the potato could light a light bulb," said Gia. "I thought that only worked in movies!"