Physics 11 – After a two year hiatus, I returned to the Phet Energy Skateboard Park. This was the student’s first exposure to energy bar charts, after having spent a class on discussing energy as storage systems, and representing energy storage in pie charts.
The handout in the picture above has some leading questions for the kids to use while exploring the simulation. They didn’t hand in the worksheet. Instead, I used some plicker questions to check their understanding.
Math 8 – Today was a pretty quiet day. The kids did some practice questions, and we spent some time going through what is a Least Common Multiple. First I had to find out if the students actually knew what an LCM is, which was a harder job than what you’d imagine.
We finished with voting on finding which ratio is bigger. This led to a good discussion on comparing ratios, equivalent ratios, and problem solving. Which is bigger, 17/32 or 17/33? This can be confusing, but students know that 17/2 is bigger than 17/33. Therefore 17/32 has to be bigger than 17/33.
Math 8 – We started class with doing a bit of Peer Instruction (PI) on order of operations. Lots of pedagogy here: choosing random students to answer questions, peer instruction, spaced practice, etc…
This student did a wonderful job of coming up to the front of the class and giving a good solution to the problem presented
The first vote had about 50% correct answers, and this increased to about 88% after the second vote.
The rest of the class was spent on an integer project (more on that later).
Math 8 – The above picture shows the 2nd vote (peer instruction). On the first vote the choices were evenly split between A, B, and C. Obviously we spent more time on this question. Pretty good evidence that this topic needs to be explicitly dealt with, we shouldn’t assume that kids know what the equals sign means. This vote was after I asked the class to consider the difference between 4×8 (an expression) and 4×8=32 (an equation).
Above shows the class collaborating and discussing a voting question.
In general, we had good Flow today…
Physics 11 – It was a short day, so today the class worked on some practice and we did our first peer instruction. The first vote had about a 18/5 split, and the second vote went 23/0. Success!
Physics 11 – One topic we (un)covered today was the Doppler Effect. We used peer instruction to help with understanding. Normally in all of my classes it’s like pulling teeth to get students to stand up, walk around and discuss questions. For today’s question I told the class that everyone would get 800 bonus points if over 80% of the class got the correct answer. The catch was that I would randomly pick one student to give their explanation, so just sharing the answer would not be enough.
The funny part about all of this is that our grading system doesn’t work on a points system and they know this. Everything is compared to standards and learning objectives. So “800 points” is a meaningless term in my classes. I had to take a photo of this because you’ve never seen a class so invested in learning about a concept. I couldn’t help laugh and a few students caught on to my “800 points” trick and rolled their eyes.
Physics 11 – The main learning activity today was to work through some voting / peer instruction questions. This one is my favorite. Students have a tough time with it until I ask them “which one, the putty or the rubber ball, undergoes the largest change in velocity?”
Physics 11 – This year every student of mine has their own Plicker card. In previous years I kept one laminated set of plickers but it was a bit of a pain to work with. It took time to hand out and collect, and it was too difficult to ensure that each student had the card number that they were assigned to. What I did this year was combine a plicker with mini whiteboards. Each student received a plicker card printed on regular A sized paper, one A sized sheet of card stock. These where then slid inside a plastic sheet protector and voila! Not only do they have a plicker card but they have an erasable surface for questions that involve writing down an answer or graph. For example, I can ask students to predict the v-t graph of an object’s motion. I still use Peer Instruction with Plickers and it continues to be a solid system to use.
Physics 11 – Today it was time again for more peer instruction. I had gone over the basics of projectiles with the class fairly briefly. Somewhat different to how projectiles are covered in BC, I delayed introducing them until after we had done unbalanced forces. At this point students can clearly identify the single force acting on the projectile and how it has constant acceleration downwards, and constant velocity horizontally. Sequenced like this, projectiles do not have any new concepts in them.
This first question required two votes, but the students had almost 100% correct on the second vote. The next question I knew would be more difficult:
The students had only one piece of the puzzle to figure out this question, and a few students picked up on it. Most did not, even after two votes. The concept that helps answer this question is that the time a projectile spends in the air depends on the vertical motion. Specifically, the more vertical distance traveled, the longer the time spent in the air.
I’m continuing to use Plickers for peer instruction, and it is working very well. The software has improved over the past year and the voting appears to be more reliable.
BC Physics 180 