Yesterday, I taught four science classes to approximately 100 eighth grade students at East Cary Magnet Middle School. The mission of the school is to be a Center for Global Studies and World Languages and motto is Unity Through Diversity. As school year just began last week and the teacher needed to attend a training, the students are getting an introduction (or reminders) on topics including laboratory safety, definitions including density and buoyancy, and the scientific method.
I didn’t expect the homeroom and “Global Scholar time” students to continue staying for the core 1 science class lasting a total of two hours! The students didn’t have much independent homework or class work to do so we had lots of time to share stories and compare interests. Many students shared they like sports, dancing, music and computer games. Given the mission of the school, I asked what languages they speak and some of the responses included: English, Spanish, German, Japanese, French, Russian, Arabic, Hindi, Mandarin, and Tagalog. Luckily for me, all the students are fluent in English. I said they are also learning to speak Science and to consider it like a foreign language that they need to learn the lingo and start with the definitions. The classroom has a couple of Science Dictionaries for Kids that I used. I also encouraged them to realize that they will be far ahead of many adults who may have taken science classes so long ago and to be aware of misinformation in the news or social media. I gave some examples as we discussed the scientific method process of making an observation, hypothesis (an educated guess), data analysis, control group, to developing a theory to explain what we observe in nature. While a theory does not sound as convincing as a scientific fact, most scientists will agree with theories. I offered examples of climate change, dinosaur extinction, evolution, and plate tectonics.
The teacher’s handout only took about 10 minutes to complete which asked for defining accuracy and precision. Thinking about the start of the NFL season, I gave an analogy of a football kicker can be accurate to score a field goal and get 3 points but if keeps hitting the same spot on the goal post he might be precise but not accurate.
The handout also involved reading drawings of graduated cylinders to compare displacement of objects resulting in a change in volume. For example, the initial water level in the tube might be shown as 10 ml and when adding a penny the water level moved up to 11 ml so the displacement is 1 ml. Some students found these concepts difficult to visualize so I found some teaching aides with a beaker and actual graduated cylinder.
I showed a glass jar half filled with water asking students to guess what objects might be buoyant or sink. A leaf floated until it got waterlogged and sank. I explained that the air filling the leaf pores enabled the leaf to float until water filled the pores. A plastic cap for a glue stick floats but a plastic push pin sinks due to the metal pin. We looked at data for density of various metals and only a few students had heard about the story of Archimedes (as explained here by NYU) revealing the king’s gold crown wasn’t pure but contained some silver.
Most students in the four science classes lasting one hour each expressed appreciation and said I told good stories and am really nice. I said I enjoy being an occasional substitute teacher averaging once a week and they need to be kind to their dedicated teachers as it takes a lot of energy and empathy!