William Ughetta ’17 reflects on his teaching experience in Tanzania:
The students were not back yet. I unpacked the batteries, bulbs, wires, and worksheets. Although I had taught the same class earlier, I was not sure how the lesson would go. I had modeled it after my own Physics classes, which focus on student learning through experimentation and discovery.
The seventh grade being small, the ten students filed into class after their break. They were surprised to see the materials in front of them, expecting another class with lectures and exercises. I started by asking the students to figure out how to turn the light bulb on, using the batteries and wires in front of them. In groups of two, the students worked together to hold the wire to the battery and bulb in different combinations. By asking specific questions and trying different combinations, students slowly figured out what worked and what did not, and, more importantly, they were able to use their observations to figure out why they behaved this way.
Students saw how the circuit had to be completely connected and how materials either conducted electricity or impeded its flow. Students recorded their observations and drew diagrams of how the light bulbs were connected. Then I showed them how to draw circuit diagrams to show the components of the circuit and how they are connected, rather than the physical appearance. While investigating how changing the number of batteries affected the brightness of the light bulb, one group blew a 1.2 volt light bulb with 3 volts (using two AA batteries), which was a learning experience because it helped show how the voltage has a very real effect depending on the resistors in the circuit. Students knew that the circuit did not work when it was not closed from experience, so they could guess that the light bulb no longer worked because the electricity could no longer flow from one end of the battery to the other. The class then set up circuits in series and parallel, drew diagrams, and recorded observations about which layout was brighter and the differences between them. Sometimes it took a lot of hands to hold the circuits together, especially in parallel (when the light bulbs are not in a row but both connected to the battery). The observing teacher even was eager to lend a hand and help the students understand.
Although I had planned to explain how the flow of electricity can be modeled by the flow of water, I had to end class since we were over time and I had to go help teach fourth grade. Before I left, I gave the supplies I brought to the teacher so he could use them later. He showed me what he had to teach on circuits in the textbook, and, although I did not cover any math, I felt that my lesson was a good introduction that helped students understand core concepts and basics of circuits. Rather than being lectured to about a topic that may have seemed irrelevant and imaginary on a white board, students were able to explore intrinsic concepts of circuits with careful observations and questions.