Science 8 – Today was one of those rare days when your students actually put an iPad to good use. I get so frustrated with the concept of the iPad (and Chromebook), as they are simply not good investments for schools that have science classes. However, today the kids go to use a phet simulation that works with HTML5, which means it works with the iPad.
The activity was very simple. The students played with the simulation which had them mixing the three primary colours, and using filters to block out colours. From their explorations the students were able to clearly say that white light is a mix of all other colours, that filters block all colours except that the colour of the filter itself, and that all colours can be made from mixing red, blue and green. Next day we will look more closely at the electromagnetic spectrum, light spectrum, and wavelengths. From that the students will have more complete picture of what a “colour” is.
Physics 11 – Today the students worked through the formula for Universal Gravitation. The students felt pretty good about how gravity works, having covered it conceptually already. However, there were still a few surprises (mostly for me).
It became apparent to me that many students consider the re-ordering of variables in a formula as something that makes a new formula. For example, after rearranging the formula to solve for r, separation, I was asked several times if the students would be given this formula on the formula sheet.
The second big surprise was being asked if the N*m^2/kg^2 units for G were variables, and what numbers should be plugged into them.
The above two misconceptions will have to be something that I specifically address again the future.
Science 9 – The classes today did a lot of seatwork / textbook questions. I looked around for different activities for modeling meiosis, and found a few. And wow! where the models difficult to follow. They made sense, but they also typically took about 20 steps of cutting, joining and mixing various pieces of strings and pipe cleaners. So I had my classes use the textbook to compare meiosis with mitosis, and even this got confusing for the students.
Leading up to this lesson I spoke with teachers that do Science 10 and Biology 11/12. It became very clear and evident that whatever processes that are memorized in grade 9 science, they are long forgotten by the following year. This revelation emphasized to me the importance of focusing on the Big Ideas in meiosis: meiosis allows for genetic variation, and the resulting chromosomal differences between meiosis and mitosis.
While the seatwork would have been somewhat boring, it did give me a chance to go to almost every student and ask them to tell me about the first two Big Ideas. In my mind, this was a fantastic way to implement formative assessment. The desired outcome is clear, and each student is given a chance to demonstrate what they know and get timely feedback. It wasn’t a perfect process, as I didn’t get to speak with every student.
Physics 11 – Ok, they’re not the greatest photos in the world, but you get the idea!
Today students conducted the experiments that they designed last class. A few groups still did not see that they should be measuring force directly in order to find friction. However, most groups were reasonably efficient in collecting enough information in order to determine if their test variable had any effect on friction.
One of the variables that is a bit more difficult to test is object speed. Moving a wooden block at different speed gives some variability in measured friction. I think this is partly due to the students’ experiments which have the blocks moving very slowly. In these cases, you can see that the blocks are moving in and out of static and kinetic friction. It was very cool to see some groups clearly state that they thought the friction changed depending if the block was moving or not.
The students did not do a quantitative lab for finding the coefficient of friction, for this activity it was enough to see if there was an effect or not. I think we will do a quantitative lab as an assessment for lab skills.
Science 8 – Grade 8 science is starting a unit on waves and optics. One of the first activities we covered was drawing a traverse wave using a vibrating marker pen drawing against a file folder that is moved horizontally. I think the students really appreciated this lab, as it was quite surprising to them that a curved wave shape could be created by two perpendicular movements. It also reinforced the concept of particles moving in one place (the marker) while a wave seemed to move along.
One extremely pleasing part of the lesson was when the student in the yellow volunteered to go first in presenting his whiteboard. This student is interested in science but is shy at times, and maybe even lacks a bit of confidence. However, he was randomly put in a group where he became a natural fit for leading the group. Not only did he show leadership in developing the group’s solution, but his willingness to share with the class was great to see.
Three excellent gifs are also used in this lesson:
Physics 11 – We used most of the class to look a how friction could be modeled on the microscopic level, and the factors that affect friction. The first class brainstormed possible factors that affect friction and then broke into groups to investigate a factor. However, a few groups had a difficult time clearly identify friction force as the dependent variable, and a variable that they could directly measure.
I had the second class work through a more structured approach to designing their experiments, where the dependent variable was more explicitly stated and recognized as being something that could be measured. We used the Smarter Science framework to assist with this. We didn’t have time to carry out the experiments, so that will be done the next day.
Science 9 – Today the students used some active yeast to observe asexual reproduction. The lab itself is quite straight forward and the students get a chance to practice laboratory skills: zeroing a scale and measuring mass, using a graduated cylinder, making a wet mount slide and using a microscope.
There are several hurdles for a large class. First, there is little room and not enough equipment to keep all students involved and practicing the skills mentioned above. Secondly, the budding is hard to identify at first. A person needs to spend a while looking through the microscope before they will recognize the subtle differences in shape of the yeast as it is budding. Lastly, students need considerable assistance in focusing on their slides. To do properly, I feel that this lab requires one hour. Some groups would finish it a lot sooner though.
Physics 11 – Having discussed and debated about Newton’s 3rd Law last day, today was a chance to put the students on the hot seat with Peer Instruction. Class #1: first vote was about 70% correct, moving to everyone correct but one person on the second vote. Class #2: first vote had over 80% correct, no second vote required.
This question was more difficult because the answer is more subtle. Class #1: first vote was about 60% correct, moving to 75% correct on the second vote. Class #2: first vote was about 60% correct moving to 90% incorrect on the second vote.
I could see how students were convincing with their incorrect arguments. The key was in the drawing of a force diagram, but very few students wanted to do this. However, as time moves on I think I am slowing convincing students just how important a force diagram is. Now that we are doing more word problems (5e: extend), I am reinforcing the idea that physics covers the force diagram and writing an equation for the net force, and then the rest of the solution is math. By skipping over force diagrams, the students are not demonstrating understanding of physics.
Science 9 – After covering many smaller details of cellular reproduction, today we finally hit some of the Big Ideas. The above is one of them. No, I didn’t give them notes! The students were asked to answer some questions for themselves, and this was sort of an answer key I had ready for them to check their work. It can be very difficult to have group discussions in one of my science 9 classes, so I have to rely on students doing their work and checking in on their understanding.
Another Big Idea:
Physics 11 – We started off with a short look back at the conceptual work we did with gravity. In particular, we reviewed how the gravitiational force between two objects is the same for both objects. This was demonstrated using some scaffolded models and a tug-a-war with force gauges. This work set a good foundation for Newton’s 3rd Law.
Having covered spring forces and gravity, the above video gave the students a convincing argument that interaction pairs have equal and opposite forces, regardless of the masses involved. Once again, many thanks to Frank Noschese for his invaluable sharing of ideas, experience and resources.
Next we came back to how we do Force Diagrams (Free Body Diagrams):
The students were now given a second reason on why they’re asked to label forces with the details of “_____ on _____”. The first reason given was that if they student couldn’t figure out the agent that was causing the force, there is a good chance that they are imagining a force that doesn’t exist. Today, the second reason given is that this description clearly outlines the interaction pair.