Modesto Tamez, a Teacher in Residence at the Exploratorium, has been
teaching science and bilingual classes for eighteen years. His first job was teaching at an inner-city elementary school in Chicago. When
dwindling enrollment threatened to close the school, Modesto helped develop a hands-on science curriculum to convert the school into a
science magnet and draw in more students. Modesto says the idea for creating a mini-Exploratorium(tm) in the classroom first came to him
two years ago in a dream. Now he's working in nine schools in the San Francisco Bay area, including four inner-city schools, helping
teachers develop their own classroom science museums.
One of the true joys of teaching is when you see the "lights go on" in a student's eyes: the lights of curiosity, wonder, and understanding. I get excited when I hook students; when they start asking and then answering their own questions, discovering for themselves that science can be fun and understandable. This is what I see when the tools for teaching are hands-on experiments that students choose and build themselves. With a little organization and effort, these individual projects can form the basis of a science museum in a classroom, a resource that can be shared with the entire school. There are probably as many ways to use the Snackbook as there are teachers to use it, but this is the method that works best for me.
Creating a mini science museum is easier and cheaper than you may think. I recently organized two science classes to build fifty-five exhibits. The exhibits took us a little over a month to complete and cost about three hundred dollars. The rewards in student pride and knowledge and the attention the mini-Exploratorium(tm) garnered for the school's science program was well worth the time, effort, and expense. You can do it too, with help from your students and the recipes in the Exploratorium Science Snackbook.
I start by selecting and building ten or twelve Snacks to demonstrate to my class. All the Snacks in the Snackbook are deliberately low tech, but some are more advanced than others. I choose easy-to-handle projects and practice building and demonstrating them before showing them to my class. When I show them to my students, I stress how easy and quick they were to assemble. To reinforce this, sometimes I actually have my students time me putting a Snack together.
On the first one or two Snacks, I go slowly through the demonstration. I spend some time helping the students figure out the science behind what they're seeing. Rather than telling them the answer right away, I try to wiggle it out of them. I'm deliberately stingy with answers: I tell my students they have to work for the answers. They soon find out that it's fun to discover the answers for themselves.
I recently used a modified version of the "Fog Chamber" Snack to introduce a class to the concept of air pressure. I stretched a rubber glove over the opening of a glass jar so that the fingers of the glove dangled inside the jar. I called for a volunteer and chose Steve, one of the larger boys in the class, to help demonstrate. I asked Steve to put his hand inside the glove. Steve tried, but much to the amusement of the rest of the class, he couldn't force his hand in. After they stopped giggling, I asked the students to guess why Steve couldn't get his hand into the glove-what was already in the jar that might keep Steve's hand from going all the way in? They answered: "air." Then I asked a smaller student, Amy, to put her hand in the glove-in-a-jar. Her hand fit in easily, which got another big laugh from the class. What was the difference between Steve's hand and Amy's hand? "Her hand is smaller and doesn't take up as much room," they answered. From that I could tease out the details: the air inside the sealed jar exerts a force, called air pressure, on the student's hand; because Steve's hand was larger and took up more room inside the jar, the force exerted on his hand from air pressure was also larger.
This is a very simple experiment, but with it I introduced a fundamental scientific principle to a class that had no previous instruction in any of the physical sciences. By experimenting, observing, and asking questions, the students experienced and learned for themselves that air has pressure. (You might want to try this yourself: see page 7.)
Sometimes I take a completely different approach to a Snack, as I did recently when I demonstrated "Doppler Effect" (see page 10) to four separate science classes. The students assembled on a grassy knoll outside the classroom while I ran to get my car. For the next few minutes I zoomed past them-back and forth-blaring my horn as they cheered and waved. The students said they could clearly hear the Doppler effect: the pitch of the horn got higher when the car moved toward them and lower when it moved away. The experiment worked beautifully for the first three classes. On the fourth and final class, as I was cruising down the street with my hand jammed full on the horn, I saw the flashing red lights of a police car in my rear-view mirror. The students, of course, were delighted.
Peering into my car, the puzzled officer inquired, "What are you doing?" As if it were an everyday activity (which, for me, it is), I replied, "I'm teaching my class about the Doppler effect." This gave the officer pause (perhaps he was wondering what kind of ticket should be issued for someone conducting noisy, open-air science experiments). A school security guard, familiar with my antics, finally came to my rescue. "It's okay," he explained, "he's just a crazy science teacher." After one or two demonstrations, I give my students some time to play with the completed Snacks. Don't worry if you can't answer all the questions the students ask or if some of the Snacks don't work the way they should. If something goes wrong, tell the class that trial and error is part of the scientific process. Tinker with the Snack and have the students help you try to figure out what's wrong. Pitching in and working together to solve a problem is a crucial part of constructing hands-on science projects.
Once the students have been introduced to Snacks, it's time for each of them to choose one of their own to build. I usually select seventy or eighty Snacks from the Snackbook that I think are appropriate for my class level. I pass them out to the class and have each student pick three to five Snacks, ranking them from their favorite to their least favorite. I tell my students I'll try to give them their favorite, but if other students choose the same Snack I may have to give some of them an alternate choice. Sometimes I opt for one of the harder Snacks rather than give a student his or her first choice, because I want to challenge those students that I know are capable of handling more difficult assignments.
After the students know which Snacks they're building, I give them a week to gather the materials. The students are left to their own resources: some materials will be in the classroom; others they'll have to find for themselves. If they can't find something on their list, I encourage them to substitute. I tell them it's okay if their Snack isn't exactly the same as the one in the book.
These two students have built a working periscope. All it took was some tape, PVC pipe and elbows, two plastic mirrors, and a little
ingenuity and imagination.
Even though each Snack has only one builder, the students often work together to find solutions to each others' problems. As ideas are bounced around the class, the students all improve their problem-solving skills. In a recent class, one of my students was working on "Mirrorly a Window" (see page 9). She didn't want to glue wooden dowels to the mirrors because she thought that it would be too messy. Instead, she decided to drill holes through the plastic mirrors. She might have been able to drill the holes herself in a high school shop class, but this school didn't have the facilities. We talked it over and she decided to take the mirrors to a plastics supply store. I asked her how big the hole should be and she found the answer by measuring the dowel. But when she brought the drilled mirrors back to class, she discovered that the hole was too big and the dowel just slipped through without sticking. Another student suggested that she could wrap some duct tape around the dowel to make it fatter. This ended up being a great solution. The tape around the dowel looked exactly right because the edges of the mirror were also wrapped in duct tape.
Using cardboard tubes, tape, and a pine board, these kids have built the "Pipes of Pan" snack from the Exploratorium Science
Snackbook. Because each tube is a different length, each resonates with a different sound.
If you have computers in your class, you can have the students use them to print out their graphics. If not, a typed or neatly written graphic is fine. It's important only that the sign is easy to read and attractive-looking, like the professional graphics they might see in a museum.
Once all the Snacks are built and the graphics completed, it's time to unveil the mini-Exploratorium(tm). The Snacks are assembled on long tables in the classroom, four per table. I assign four students at a time to be "Explainers," science guides who answer visitor questions. This means that the students must be familiar with all the Snacks, not just their own. You can invite the whole school to the mini-Exploratorium(tm). I'd also suggest a special parent's night exhibition. If you invite school administrators to the event they might be so impressed with the students' work that they loosen the purse strings for other innovative science programs. It also doesn't hurt to call up the local press and toot your horn: the positive publicity makes you, the principal, and the school look good.
But the real benefit of a mini-Exploratorium(tm) is for the exhibit-builders themselves. Putting together hands-on experiments involves much more than learning about science. It also builds skills in reading, planning, writing, artwork, using a computer, problem-solving, presentation, teaching, and interpreting science. Having the students select their own Snacks is important; it empowers and engages the students. Planning, problem-solving, and hands-on activity keeps them interested in concepts they might otherwise find tedious and difficult. Having students share their new-found knowledge with others reinforces and cements the concepts: as any teacher or writer knows, you must first understand a concept before you can explain it to others. The combination of all these activities is a very powerful, engaging, and fun way to build learning skills.