Of Scabs and Showers: Teaching Science In Middle School

Montessori Life, Spring 2004 by Cherath, Lata

"Dr. Cherath, can we please look at my blood under the microscope? I just pulled this scab and there is so much blood. Please, it'll be so cool." It was Tuesday and I had an hour long lab session with second and third year middle school students. Our school had just purchased six new microscopes and I had planned to introduce them to the microscope, its different parts, how to use fine focusing and how to learn about depth perception using three different colored yarns.

"Yes, please let's look at the blood cells," I was asked again. A part of me wanted to continue my agenda, but when else would I have this fresh supply of blood and this interest? I showed the students how to put a drop of blood on a slide and place a cover-slip on it, taking care not to trap air bubbles. Soon 16 heads were bent over the microscopes eagerly examining Christopher's blood cells. They had a hundred questions to ask, and they wanted to examine hair, nails and even some skin cells which one student had scraped from under a cast on her arm.

By the end of the lesson not only did the students learn how to use the microscope, they also had a lot of fun doing it. In the five years since I have been teaching science at Princeton Montessori Middle School, this is a lesson that has been ingrained in me. When a lesson is interesting, appealing and connected to their everyday lives, they get the most out of it.

Middle school science is the delicate balance of teaching scientific concepts without being too "elementary" nor too "high schoolish". The ultimate objective as always is for students to become self-learners, to be curious, to dare ask questions and experiment, and to make discoveries for themselves. Yes, there are certain facts that they have to memorize and internalize, just as many had to memorize the multiplication tables in earlier years. These facts enhance their understanding and give them a foothold as they reach for an increased understanding of other principles.

Flexibility in Lesson Plans

Having a specialized degree in science is extremely helpful in teaching middle school students, and it affords the teacher great flexibility to change the lesson at a moment's notice. A case in point: When we were doing a unit on volcanoes, the devastating earthquake in Iran happened and students heard about it on the news. A student of Iranian descent talked of her weekend with her family all glued to the Iranian TV news. I could not let that moment slip by. I drew the connection between volcanoes and earthquakes and explained that both occur at plate boundaries and that earthquakes foretell the eruption of a volcano in volcano-prone regions. Once I captured the students' attention, the class took on a momentum of its own. By the end of two weeks the students had designed earthquake-resistant buildings and were eager to test them.

Hands-On Learning

Science at Princeton Montessori School is, of course, a hands-on learning experience. We experiment, have debates, play games and the students design fairly complex gadgets. Students who were studying magnetism this year designed a vending machine which could detect fake coins. They used metal washers as the fake coins and a bar magnet was the detector. In a separate unit on electromagnetism, they built an electromagnetic fishing rod with an off-on switch that can lift paper clips from one container and drop them into another.

In the unit on volcanoes students made a documentary about life in a volcanic region using a variety of media. These were projects requiring communication and collaboration. I always emphasize that communication is one of the cornerstones of science and scientific discovery.

Showing Connections

One of my main goals in teaching is to improve the students' understanding of how science and technology relate to their daily lives. Sometimes I am asked, "Why do we need to learn all these principles-Bernoulli's and Pascal's? We will never need them again." I reply, "Once you realize how these principles affect your lives, they won't seem so bewildering."

One day we talked about Bernoulli's principle which states that the faster a fluid moves, the less pressure it exerts. As an exploratory activity the students held plastic spoons loosely by the handles so the spoons would swing freely between their fingers. Then they turned on the water faucet to produce a steady stream of water and tried tobring the curved back of the spoons in contact with the water. Many predicted that the spoon would be pushed away, but they found the spoon was pushed toward the water. This was because the water running along the spoon is moving, but the air on the other side of the spoon is not. Moving water exerts less pressure than still air. As a result the greater pressure of the still air pushes the spoon into the water.

We did several such activities and then one student observed that the reason a shower curtain sometimes hits you in the leg while you are taking a shower is because the still air on the other side exerts more pressure than the shower water. "That's an example of Bernoulli's principle, isn't it?" Everyone could understand that and learning didn't seem all that bad anymore.