Stage 8: Functions with Backpack Charms


Backpack Charm-J

Backpack Charm-J


The past two days we have been working with Stage 8 Unplugged Coding Activity which is essentially making what my kids call “Backpack Charms”. has called them “sun-catchers” but honestly, my kids don’t really know this word.  If they don’t know the word, it can’t be “cool”.  We have these little dangly jewels that girls love to attach to their mobile phones called mobile phone charms.  We’ve decided to call these larger things “backpack charms”.  Guys can call them key fobs.

The unplugged activity is basically to string together a pattern of objects.  Then, we had to make Programming instructions for the pattern.  Along the way, we were able to talk about the term Ambiguous (being unclear).

labelled Vivian's Suncatcher small

In the above example, you can see the Sequence of objects goes like this:

  1. Binary (I used “Shrinky-Dink” plastic to turn my first initial as a Binary Code into a “charm”.   The instructions suggest parchment paper.)
  2. Bead
  3. Knot
  4. Bead
  5. Knot
  6. Spacer
  7. Knot
  8. Bead
  9. Knot
  10. Bead
  11. Knot
  12. Spacer
  13. Knot
  14. Special Charm (I used a special button shaped like a leaf, but this could be something made out of Fimo. See the pic below of a Minecraft block that we made out of Fimo.)
  15. Knot


Minecraft Block made out of Fimo

Minecraft Block made out of Fimo could be the “Special Charm”

Binary Code Initial using Shrinky Dink plastic

Binary Code Initial using Shrinky Dink plastic


The 15 lines are the Program.  The terms bead, spacer, knot etc. are the Variables (The notes say that the definition for a Variable is a placeholder for a value that can change.  The word “spacer” is a placeholder because you can assign this word to represent anything you want in the sequence ex. a star button, a hoop, a bead, a ribbon)

At this point, I challenged my children to figure out a way of grouping together parts of the sequence and renaming it so we wouldn’t need to write so much.  This grouping together of instructions is what is called a Function Definition.  As an example, we could group lines 2, 3 & 4 and rename this as a Function called “Skills-1”.   Instead of writing “Bead”,  “Knot” , “Bead” we can call upon Function Skills-1, which is the exact same thing but in “short-hand” form.

I sort of thought this step would be quite straight forward; my children range from the ages of 9-17.  In fact, it took quite a lot of arguing and many tries before we could make the Program  contain the fewest lines.  We talked about Efficiency along the way which would be the most stream-lined piece of coding, or the program that needs the fewest lines.

Function & Program small


On the worksheet above, you can see the two Functions that were made called Skills-1 and Skills-2.  The program with the fewest lines, which was 4 lines, is circled in yellow. In the Program on the bottom of the sheet (circled in yellow), you can see the two Functions Call (the place in the program where you call a Function you have defined).

We have two “Skills-1” in the program. They are Functions, remember…

A Parameter is a value that is passed into a Function.  So, I  if we put the following as one of the lines of our program:

  • 2 Skills-1  (Do Skills-1 twice)

that the 2 would be the Parameter….

Well, I hope I got this all sorted correctly and hopefully my explanations make sense. There were a lot of concepts packed into this activity.   We wrote out the Program on one day and then did the beading on the following day.

Younger students could do this with pipe-cleaners.  If you don’t want to involve sewing, you could use yarn instead to string the items together.  A bonus was that my boys learned how to sew a button down!  One tip I could offer is to provide blue-tack so students can practice sticking down their beads, buttons etc. in a row before attaching them permanently.

It was a fun activity and now we have five Christmas tree ornaments hanging on our Christmas tree!

Happy Coding!


L Suncatcher small

About Vivian

Vivian @ChezVivian is a Canadian-born Chinese, currently living in Switzerland. She has also lived in Hong Kong and Indonesia. She holds a M.S. (focus: Educational Technology Integration), B.Ed and a B.A. and graduate studies in Kodály and Orff music pedagogy. She is an elementary school classroom generalist, but has also taught as a music specialist, ESL/EAL and also in Learning Support. Most of her teaching career was in International Schools in Hong Kong. She is excited about the IBPYP and the possibilities of using technology to Inquire. Recently, she has been looking at the opportunities that computer programming gives to put #TECHXture back into the hands of children. In other words, technology need not be just about looking at screens. It can be about building things with our hands; and computer programming levels-up what children can do with the things they build---encouraging higher thinking skills. She is a Coetail Post-graduate Certificate grad ('13-'14), a former Coetail Coach and one of the co-founders of #CoetailChat. Her blog home curates her assignments for Coetail and her M.S. graduate studies about Educational Technology integration and anything else educationally-related that she feels inspired to write about. Her twitter tagline sums it up: "Mom to 4, Mentor, Educator, Musician (in that order)".
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2 Responses to Stage 8: Functions with Backpack Charms

  1. K hewins says:

    Thanks for this explanation. When I read the directions on I pictured s suncatcher but is obviously not the same that they ‘pictured’. Your sample was more on target.

  2. Vivian says:


    Thanks so much for taking the time to let me know this blogpost helped. I wasn’t sure if anyone was doing the unplugged activities, so it’s good to know that some people are…

    My idea of a sun-catcher isn’t like what they want, either. A sun catcher, to me, has a flat geometric shape and is made of coloured glass or plastic.

    I called it a “back pack charm” as it looked too big to be a cell phone charm. To me, what they are asking for is a LONG cell phone charm.