Day 77: Exam Review

Friday, 5 December 2014


I promised the kids an exam review today even though the exam is over a week away. My goal is to encourage students to prepare for the exam over a longer period of time. And since my past experience shows many students don’t start prepping till review day, I wanted to encourage good study habits.

When they got to class, I handed out whiteboards and markers, and told them to outline a unit we studied. We then assembled all the boards along the front of the room and read each others’ work. We discussed big themes that popped out as well as “oh crap, I forgot all about that” moments. I then highlighted anything I felt was missing. In one class, the kids asked me to solve an echo problem because they remember feeling like that was difficult at the time.

Here are some of the whiteboards we created on Friday.

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Days 72-76 Light Bulbs Lab

Friday 21 November through Thursday 4 December, 2014


I’ve decided to post highlights from an entire week for the remainder of the year. So, here’s the Friday before Thanksgiving break through the whole week after break. We’re closing in on the end of the semester, so there are some potpourri activities going on in here.

First off, we all did the light bulbs lab (here it was in 2013). This has proven a great method of teaching how parallel and series connections work before kids learn about resistors, which I think are more abstract. The biggest struggle this year for most kids was with moving from the wiring schematic to the physical configuration.

We run through eight circuits over approximately two days of work. My only wish was a better way to connect light bulbs to resistors, which we study next. Specifically how resistance adds in series and parallel. Below, I demo a part of the lab for you.

Day 71: Classwork

Thursday, 20 November 2014

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It’s amazing to me how much kids struggle at question 1.

How many electrons do you need to make up a total charge of -1 coulomb? The kids know that an electron has a charge of -1.6×10-19 coulombs. Why, then, is it so hard for them to divide the total charge (-1 C) by the elemental charge (-1.6×10-19 C)? My guess is that it’s because the charge on a single electron is impossibly small — that the scientific notation is distracting them. My suspicion is confirmed because when I change the numbers to 100 C total charge and each element possessing a charge of 10 C, they totally know what to do.

Day 70: Lecturing?

Wednesday, 19 November 2014


These are notes from a lecture I gave today. I’m not happy with the process at all and this is the one time all year when I wish I did forces first — knowing Newton’s Law of Universal Gravitation would make introducing Coulomb’s Law simpler.

On the upside, the board is neat, sequential, and easy to follow. But then again, Veritasium has taught me that clear, concise, and easy to follow mean almost nothing for learning.

Day 69: FIRST Pneumatics Training

Tuesday, 18 November 2014


The least efficient machine ever.

I help coach FRC team #2415 and our fall pneumatics training included a project teams of two kids came up with. One group wanted to use pneumatics to operate a bike pump to launch a rocket. Yes, we realize the complete Rube Goldberg-ishness of this machine that uses compressed air to compress air to launch a rocket. They were the first group to get to prototype stage, as shown above.

Another group is using pneumatics to turn a small car’s wheels and the final group is operating a claw gripper. They’re not ready yet with prototypes.

The training module was taught by a senior and I helped guide it. About a month ago, we also built the FRC Pneumatics System as shown here.


Day 67: Discovery Trip

Friday, 14 November 2014

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Taught two classes then skedaddled out to AH Stephens State Park for a weekend expedition with 10 freshmen, 3 outdoor (student) leaders, and one other faculty member. Above are all the students on expedition. Read more about Discovery, our outdoor and experiential ed program that all freshmen take part in.

This was our coldest weekend of the year so far — Friday night while we were still awake, we saw temps as low as about 30°F. The kids were troopers, though. They happily cooked dinner, cleaned up, and stood around our massive campfire talking. Friday night dinner was silver turtles. The students do all the prep work and cleanup, making this the easiest faculty supervision I have all year long.

Over the rest of the weekend, we went geocaching in the park and did other camping stuff like hanging out by the campfire. Did I mention it was cold?


A group of our kids hunt for a geocache while on weekend expedition.



Day 66: Test Corrections

Thursday, 13 November 2014


The question. I asked student to solve for magnification.


Here’s the correction for the above problem. She solved for the focal length incorrectly at the start of the problem but all other work was correct.


This kid mostly got the correction right — they did indeed forget a negative sign. I felt it was bit too nitpicky of me to say that the “decimal in the wrong spot” is really a unit conversion problem.

Examples of good test corrections. I recommend building in about 20% of the test time to dedicate to corrections. That is, I build tests that should take 50 minutes plus 10 minutes of corrections.