In my last post about the science curricula that I don't use, I said I would give an example of my approach to science education. This is that example: a six-week unit study on electricity and electric circuits that I designed for third grade. I really think you could expand it out if you wanted to, maybe into 9 or 12 weeks.
Week 1 Electricity and Circuits -Basics
Library read-alouds: Berger, Switch On Switch Off. This is from the popular and, in my opinion, well-designed series of picture books "Let's-Read-And-Find-Out-About Science." It's a basic introduction to the concept of electricity and electric appliances.
Epstein, The First Book of Electricity, Ch1, "What we Know." The "First Book" series of nonfiction is an older series, very well-written, generally by authors who have some expertise in the field. They are probably in your local library.
Obviously, with any older science series, some material might be out of date. This is one place where it's helpful to have a decent background in science: I recognize that when I see it, and I work around it. For example, if I've got an older book about chemistry, I might run into a picture of the old Bohr model of the atom -- the one where the electrons are orbiting around the nucleus like planets around the sun.* This isn't a problem. I show the picture, I say "this is what people used to think an atom was like," and then I grab a textbook or science encyclopedia, or I do a quick Google search, and explain what's changed in the last fifty or sixty years.
So why use old books? Well -- I like to use well-written books. That's why.
Safety information in Snap Circuits. The Snap Circuits kit comes with a book, and the book has the experiments in it, and in the front there is some brief information about safety (and how not to accidentally destroy some of the kit components). We went over that first. It's also an opportunity to convey some general information about laboratory safety.
"What is a circuit diagram?" I taught this topic straight out of my head, but you could also use an introductory high school physics textbook or -- face it -- Wikipedia as your source. The concept I wanted to get across is that a circuit diagram is a way to unambiguously communicate the wiring of the components a circuit, and that it's the connectivity of the nodes, not the lengths or orientations of the connections, that are meaningful.
I drew an example circuit with a switch and a light and a battery, and then as an exercise I had my son draw one with a switch and a DC motor and a battery. By a remarkable coincidence (cough) these are the first two projects in the Snap Circuits book. So:
Project 1. Electric Light and Switch.
Project 2. DC Motor.
I required him to draw the circuit diagram, show me, then build the circuit. Along the way we could talk about how the Snap Circuits kit is set up so that it looks like a circuit diagram when it's put together: the resistor is embedded in a plastic modular bit that has a little resistor symbol on it, for instance.
And this concludes the first week.
Week 2 Electricity and Circuits - How moving magnets generate electric current
Branley, What Makes A Magnet. Another "Let's Read And Find Out About Science" title. I brought in information about magnets to create a context for talking about electric current generation.
Epstein Ch2. "Making Electricity" -- generators.
Epstein Ch3. "Measuring Electricity"
Make the "electricity detector" in the back of the Epstein book. (It's a simple galvanometer made from a cheap compass.)
"Making electricity" project in back. (Simple, basic project -- you produce electricity in a coil of wire and then you use your little galvanometer to detect it.)
Week 3 Electricity and Circuits -- Resistance; Series and Parallel
Discuss "resistors" and "resistance." I explained Ohm's Law for this one, and we did a few math problems with it.
Project 4. Adjusting Sound Level.
Discuss "series" and "parallel" -- We talked about the difference between wiring two elements in series and wiring them in parallel. I talked him through understanding how the total resistance in a two-resistor circuit depends on whether resistors are wired in series and in parallel.
Project 5. Lamp and Fan in Series
Project 6. Lamp and Fan in Parallel
Week 4 Electricity and Circuits -- Conductors and Insulators
Epstein Ch4. "Conductors and Insulators"
Project 7. Light Emitting Diode
Project 8. One Direction for LED
Project 9. Conduction Detector
Week 5 Electricity and Circuits -- Application
Epstein Ch5. "Wires in your Home"
Epstein Ch6. "Electricity At Work"
Project 13. Two Speed Fan
Project 14. The Fuse
Week 6 Electricity and Circuits -- Having Fun With It
More Snap Circuits projects as desired. (Caveat: I made a rule that he has to draw the circuit diagram for whatever it is he wants to do. I provided him with a list of circuit element symbols and helped him to figure out some difficult ones.)
Begin Stillinger, Battery Science (a Klutz book that comes with materials)
Assign a report about some aspect of electricity.
Identify topic and go to the library
Week 7 Electricity and Circuits
Work independently through Battery Science
Outline report and first draft
Week 8 Electricity and Circuits
Work independently through Battery Science
Edit first draft and begin second draft
Week 9 Electricity and Circuits
Work independently through Battery Science
Report due.
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*The book doesn't actually have to be all that old to have an out-of-date atomic model in it. Science books for kids are not infrequently out of date before they go to press.
How cool!
Posted by: Jamie | 20 November 2011 at 03:46 PM
wow. I think I need to go back to 3rd grade science . . . I don't think anyone ever taught me how to read a circuit diagram.
Posted by: sara | 20 November 2011 at 08:10 PM
Sara, in my philosophy electric circuits, and consequently circuit diagrams, are an elective at the third grade level. But if my kid is going to be playing with electric circuits, he ought to be able to draw them.
Posted by: bearing | 21 November 2011 at 09:02 AM