Computer Science Teacher
Computer Science Teacher - Thoughts and Information from Alfred Thompson

January, 2006

  • Computer Science Teacher - Thoughts and Information from Alfred Thompson

    Teaching Binary to Small Children

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    One of my readers (thanks Blake) sent me a link to an interesting web page that uses the Socratic method (asking questions) to teach binary numbers to very small children. It is amazing how simple it all seems in the context of that example. I remember learning different number systems when I was fairly young. I remember it just being cool to me. I didn't see any use to it at the time. But even though I didn't like math much at that age I spent a lot of time for a while playing with converting from one number system to another.

    Certainly when I came across it again in college it was old hat to me and that was helpful to me. Number systems do not seem as though they are taught as often as they used to be. I think that is too bad. Number systems, not just binary, are pretty interesting. In computers we use different number systems regularly. Binary of course. Also hexadecimal and octal though mostly as a way to organize binary numbers.

    Recently I've heard discussions about devices that have three states rather than just two. Perhaps they are -1, 0 and 1 though unless you are into the hardware it probably doesn't matter much. What will matter is that this allows for a computer that uses a ternary number system. Think of the possibilities - more data in less space, more powerful instruction sets, and of course yet another number system to learn. If we teach binary correctly this should not be a problem. Though of course if we taught decimal in more general terms allowing for students to understand binary (and octal, ternary and hexadecimal) we probably would not have so much trouble with lots of concepts either.

    And that, really, is the heart of the value of teaching binary to young students - it helps them understand decimal better and at the same time opens their horizons to new ways of looking at numbers. That seems like a good goal to me. If we use the carrot of "computers use this" to get them interested that is not such a bad thing either.

    BTW I think that "how would a ternary computer change the way computers work?" might be an interesting discussion question in computer science classrooms.

  • Computer Science Teacher - Thoughts and Information from Alfred Thompson

    Job Statistics

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    One of my co-workers, Sam Stokes, put together a list of statistics about job projections in the US IT industry. I've copied a bunch of them here. Links to the origional data is supplied so you can see the details for yourself.

    Computer software engineers, applications

    • Number of jobs in 2004 was                                                               460,000
    • Number of jobs predicted in 2014 will be                                          682,000
    • Increase                                                                                               222,000
    • Percent Increase by 2014  (Increase of jobs/jobs in 2004*100)          48.4%

    Computer software engineers, systems software

    • Number of jobs in 2004 was                                                               340,000
    • Number of jobs predicted in 2014 will be                                          486,000
    • Increase                                                                                               146,000
    • Percent Increase by 2014 (Increase of jobs/jobs in 2004*100)           43%

    Computer systems analysts

    • Number of jobs in 2004 was                                                               487,000
    • Number of jobs predicted in 2014 will be                                          640,000
    • Increase                                                                                               153,000
    • Percent Increase by 2014 (Increase of jobs/jobs in 2004*100)           31.4%

    Computer Scientists and Database Administrators

    • Number of jobs in 2004 was                                                               104,000
    • Number of jobs predicted in 2014 will be                                          144,000
    • Increase                                                                                               40,000
    • Percent Increase by 2014 (Increase of jobs/jobs in 2004*100)           38.2%

    Network and computer systems administrator

    • Number of jobs 2004 is                                                                       278,000
    • Number of jobs predicted in 2014 will be                                          385,000          
    • Increase                                                                                               107,000
    • Percent Increase by 2014 (Increase of jobs/jobs in 2004*100)           38.4%
  • Computer Science Teacher - Thoughts and Information from Alfred Thompson

    Cartoons as inspiration for projects

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    I saw this cartoon the other day. It's fairly funny but there is more to it than meets the eye of ordinary people. The binary actually represents a message for the true computer person. When you saw it (if you haven't yet go ahead I'll wait) did you decode it? Would it even occur to your students to decode it? We don't teach much in the way of binary or ASCII any more. I think that is a shame.

    Now in the old days a lot of people knew the ASCII table by memory. OK not me but I know people who did (and still do). So as soon as one of those people told me he laughed at the decoded message but didn't tell me the punch line I knew I had to decode it myself. Since I didn't have an ASCII table handy and I didn't really want to do the binary to decimal by hand I did the only logical thing. I wrote a piece of code that converted a string of ones and zeros to a decimal and then displayed the ASCII value. I used Visual Basic .NET because I always use VB for string manipulation. But I suppose a good programmer (or even a beginning student - see the project potential here?) could do it in what ever language they are comfortable with.

    It's a nice little project when you think about it. A little string manipulation with a simple loop and you are pretty much all there. I think I used about 8-10  lines of code including the variable declaration, the return code (I created a function to convert the string to a decimal so I could reuse it later) and the display statement. So you could probably even do this as an in class demo, quiz or short project. And students seem to like things that look like codes, ciphers and secret messages.

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