## Thursday, May 08, 2014

### Can You Explain the Binary Clock?

Some years ago my wife bought me a binary clock. I have it sitting on my desk at school facing the students. It drives the students crazy.

What is it?
A clock.
How is that a clock?

We do cover binary numbers in class. And while they seem to get the idea and do well on worksheets and quizzes somehow making the application to the visual artifact of the clock is hard for them. The other day I had several students ask for a more detailed explanation of how it works. I thought that sounded like a reasonable request and started thinking about some visual aides to make it go better. Being a programmer a program seemed like the best solution. Maybe PowerPoint or similar would work for some people but not me. So during my lunch break (and some of a prep period) I created a binary clock program. It looks like this:

There are two columns each for hours, minutes and seconds. I added position indicators on the right hand side to show the ones, twos, fours, and eights digits. Along the bottom I show the value of each column. This makes it easy to read that this image was taken at 1:17 and 9 seconds. The totals and position indicators are scaffolding and there are buttons to make each set disappear. I also have a stop clock button so we can deal with a static time or set a specific time for discussion purposes.

The class discussion went pretty well. By the end of the session I had students calling out the time displayed, even without the scaffolding, as I changed the static display. I plan on using this as an integral part of binary discussion in classes next school year. I am hoping that making it all more visual and perhaps letting students manipulate virtual clocks themselves will help then internalize the concepts better.

I rushed the code a bit so it’s not really sharable now. I am thinking about assigning something like this as a project for my advanced programming students. I’m looking forward to what they come up with for solutions.

BTW my primary list of Resources For Teaching Binary Numbers can be found at this link.

#### 1 comment:

Unknown said...

That's a really great idea. I used to teach binary and would have been very helpful. It's amazing what we programmers can come up with when the need arises. In my case, I teach in a computer lab and we were always losing track of time. So many years as go, I wrote a computer clock program to remind me of how much time we had left and play an alarm when the bell was about to ring. I didn't realize how needed this type of program was in the regular classroom until other teachers began asking for it. I've been giving it to teachers for free ever since. Wow, did they love it and suggested new ideas to add and make it even more useful. Feel free to look at it yourself and share:

http://www.timcraig.com/classroom-clock/