Fizzics

I had a surprise on the last day of term.  I knew it would be hard to have a double period of my vocational electronics class.  Soldering can work wonders for focusing the mind and keeping everyone on task but prototyping circuits in reusable breadboards is a different matter.  Add a few pupils who have already completed their practical unit and you have the ingredients for a difficult last day before the holidays.

One of the outcomes I had set at the start of the week was for everyone in the class to know how to use a resistor colour code chart to determine the value of a resistor without having to make a measurement.  I had pinned a snappy poster on to the classroom wall close to where the resistors are kept and, over the course of the week, I noticed that pupils had become more independent - choosing to refer to the poster instead of asking me to tell them the value of the resistor they had picked from the tray.

At the start of the second period, two boys asked if they could do revision for the NAB they would be sitting after the holidays.  Could they also make up some revision questions on a sheet of paper?  I was surprised and delighted that they had come up with the idea, these things just don’t happen in this cohort.  Their quiz comprised 10 general questions on electronic components and their uses, followed by another 10 questions where the a given colour combination had to be converted into a resistance.  

It was easy to ask the first half of the quiz to the class but what about the colour band questions?  Well, I loaded up The Gimp for mac (Windows version available here) and created a “blank resistor” template for the boys to modify on the IWB.  They quickly drew in the colour bands by hand and saved each as a new page in the Notebook software.  Their willingness to produce drawings was unexpected and I captured each one as a gif file to keep for use again.  A cartoon I saw yesterday reminded me of Friday’s events and I pulled the images into Keynote and exported the presentation as a Quicktime movie.

Try the quiz yourself.  Each resistor appears twice.  The first slide shows the bands, the next displays the resistor and it’s value so don’t click through too quickly.  You’ll need a colour code chart.

Download

I’m not posting this because of the ICT being used.  I’m trying to convey that, when you least expect it, even a bunch of boys treading water until they can apply for apprenticeships can surprise you.  Perhaps they thought they were having a “skive” on the last day of term.  Whatever their motivation, I saw them take control of their learning, make excellent use of ICT and assess their peer group.  All this within two hours of the October fortnight.

I had a moment last week when I realised that I could model exactly how a problem-solving strategy would look to pupils as they stared down at the jotter in front of them. I was trying to show my new Higher Physics class how to find resultant displacements and forces by adding vectors. This is the first time I have taught the higher course and, while I would probably resort to trigonometry myself, I had to demonstrate the scale drawing method as it can prove useful when several vectors are involved.

I wanted to show pupils, step-by-step, how to measure angles and draw the lines representing the vectors to an appropriate scale. I tried begging an old blackboard protractor from the maths department but there didn’t seem to be any going spare. In desperation, I turned to the SMARTBoard software on my mac, even though the room I was using at the time had no IWB installed†. I found a brilliant protractor and ruler that I could easily move around the screen.

The best thing was that the protractor and ruler are such a good match to the physical equipment the pupils have to use when it is their turn to tackle the problem sheet. Actually that wasn’t the best thing. The total best thing was doing a scale diagram with these tools live in front of the class and coming within 0.4° of the angle they obtained using trigonometry

†This is probably a gross breach of the EULA. Sorry about that. Yes, really.