Day 134 – Finishing Momentum

Air Track Collision.gif

Physics 11 – We did a bit more practice with conservation of momentum today, along with some Peer Instruction voting.  To help with one question, I fired up the good old air track, shown in the video above.  The air-track is good but it’s limited by the carts that I have for it and the lack of a good spring plunger.

One of today’s voting questions is below.  I keep forgetting that this is pretty tricky for physics 11.  On the one hand the correct answer is intuitive.  You load something up with more mass it will slow down.  Using the concept of total momentum being conserved is harder though because students want to know what happens to the momentum of the rain falling.


I briefly talk about how momentum is a vector and we have to consider that momentum that are perpendicular do not add together as a single number.  I then quickly try to change the topic as this is waaaay above where we’re at with the topic.

Day 26 – BEDMAS PI


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).

Day 17 – Equivalence

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…

Day 144 – Peer Instruction on Doppler Effect


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.

Day 131 – Circuit Voting Peer Instruction


Science 9 – We did lots of Peer Instruction in class today, here are a few of the questions.  Students were able to make progress going from one question to the next, but as always is the case in my classes, it was difficult to get the kids to walk around the room and talk to people that were not their friends. At one point I had them walking around but they stayed in their groups…