Electricity and Magnetism

The students in 3^rd and 4^th grade spent eight weeks studying electricity and magnetism. One objective for this unit was to prepare the students for an upcoming Read Aloud, The Boy who Harnessed the Wind. This touching autobiography tells how at age 14, in poverty and famine, a Malawian boy built a windmill to power his family's home.

Before reviewing how electrical currents work, children were asked to share what they already knew. Some wrote, “Electricity makes things go.” Another wrote “You need batteries. You need magnets and you need wires.” We studied a modern light bulb, drawing what it looks like and we made our own one. In our own light bulb we tested a variety of materials as filaments to see which materials would glow and why! To answer the question, How does the flow of electricity in a series circuit differ from the flow of electricity in a parallel circuit we removed one bulb.  Figuring out why the other two lights remained on in a parallel circuit was a challenge.

When we switched to magnets and magnetism we again asked children what they already knew. “You can create magnetism.” “South and north on a magnet will stick together and south and south or north and north will not stick together.” Then we posed the question, “How close to a paper clip does a magnet have to be before the clip moves toward the magnet? We also compared how one, two or three magnets behaved. Were they stronger when working together? As in all hands on activities there were lots of opportunities to expand our understanding. Often we did this by asking questions such as: What is happening as you move the magnet toward the paper clip before the clip moves? Why are we experimenting three times and then averaging the results? How many millimeters are there in a centimeter? Using iron filings we found it fascinating to observe and draw the magnetic fields around bar magnets and circle magnets. We worked to make our own compass and explored how it works.

The final part of this unit involved BOTH magnetism and electricity. We made our own battery powered compass and finally created an electromagnet.