Sunday, January 26, 2014

How I teach programming to 7-11 year olds using Scratch

Many years ago I downloaded Scratch and did what I do with most programs, tried to make sense of it through trial and error. After an hour or so I gave up. I had no understanding of the underlying principles of sequence, repetition, selection or how a variable could be used. Pure trial and error left me frustrated and alienated from this wonderful programming tool. I wonder how many other teachers have had similar experiences.

Start simple with everyone
These days I start with very simple programming projects for all KS2 pupils. You wouldn't expect a pupil to understand or use long multiplication without understanding of a number system in place.  My early projects (Smoking CarMusic Machine & Dressing Up Game) link very simple key board inputs or mouse clicks to a single command or simple sequence. Promoting the idea that we can decide what each key does and that the programmer is in control of what the program does. I demonstrate how to connect these and then pupils copy the blocks and test their code. Lots of pupils finish quickly and I then give them specific challenges which use the same type of blocks to do something similar but where I haven’t shown them the solution. They love this! If you have time, projects where pupils re-purpose similar code work well. After our music machine I encourage them to make their own instruments. This also makes a good assessment opportunity.

Link new computational ideas to real world examples
When we encounter selection for the first time I relate this to real world examples inside the Scratch blocks. These examples are not perfect but relate existing knowledge to new. Before the selection parts of the Maths quiz I use theseexamples. When we encounter a repeat x times loop for the first time I get pupils dancing steps. Breaking a popular dance into its basic elements and then choosing notation for each element. Pupils can then design dances for each other combining notation with number of times to use, which is a repeat x number loop in the real world. We then take this knowledge straight back into Scratch.

Run through more complex code examples line by line before demonstrating code
If modelling a program that uses variables, I use a box(s) and pencils/post it notes (depending on context) and go through the code line by line. I do this with lots of programs that include variables. If you just run the code it runs too quickly to see what has really happened. I always get pupils to help me. You can also get pupils to demo their ideas for code by modelling it to you or their peers especially if you know that writing it down will take too long.

Multiple coding opportunities
Don’t fall into the trap of thinking that as you have used selection in one program that you have covered this. This is like using addition once and then thinking that you don’t need to use it again. Selection, repetition, variables are constructs you could take a lifetime to learn how to manipulate. Pupils need multiple opportunities to use and experiment with these ideas. The new English Computing program of study talks about, “repeated practical experience of writing computer programs” in the aims, lets work towards this.

Open ended environments
When choosing a main programming environment choose one that can grow with your pupils and is open ended rather than closed. Choose one where they can learn from others not just you. Scratch is fantastic for this with its excellent online portal. Between the ages of 7-14 pupils can progress from Scratch 1.4 into 2.0 and then onto Scratch ports likeSnap. You can even have different pupils using different versions in the same class depending on need. Be wary of expensive products that offer to solve the ‘Computing problem’ by dumbing down and limiting what can be achieved. What you probably need is good CPD. The CAS (Computing at Schools) website is a great resource for this with lots of quality CPD being advertised every month.


Computing is a fantastic tool for proving Maths concepts
In response to one of my schools need to improve their maths results I started writing Scratch modules which worked with Maths concepts. We have investigated counting using a number machine (IMHO one of my best modules),perimeter after revising greater than and less than. Created programs to calculate the angles of 2D shapes, programs to calculate what coins our change could be given in and much more. I feel I have only scratched (pardon the pun) the surface of what is possible. I though pupils would revolt over creating these rather than games so was really surprised when we had visitors and they choose to show these programs. In the long run you could reap real maths benefits from choosing programming environments that are open ended.

If you are in the South of England why not come along to our Primary Computing Science Conference at University of Southampton on 2nd of April.

If I can help you or your school please don't hesitate to contact me.

Phil Bagge (26th Jan 2014)

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