Saturday, February 21, 2009

Scratch challenges update

The way I have introduced scratch this year to students (years 10 and 11 in my case, but it might work with younger students as well) has been to:
  • first ask them to complete the scratch cards provided at the Scratch MIT site
  • then to complete the following challenges

1) Make 2 different balls move around on the stage
a) the first ball moves in straight lines but bounces randomly whenever it hits the edge
b) the second moves randomly, changing direction all the time

2a) One sprite chases another sprite around the stage. The first sprite moves in straight line but bounces off the edge randomly. The chasing sprite chases the first sprite but is moving slower.
b) Extension – if the chasing sprite catches the other sprite then it says something sensible and makes a suitable sound

3) Use the Letter shapes to write your first name on the page. Then introduce some special effects such as making the letters wobble and change their appearance.

4) Point, click and move
Make an object both point and glide towards the mouse position when you click on the stage
Hint: Motion > point towards
Hint: Sensing > mouse down?

5) Make two animals have a forwards and backwards conversation
Hint: Use broadcast

6a) Play all the different drum sounds automatically
Hint: create a variable for the drum number
b) Extension – keep recycling through all the drum sounds automatically

7) Make Dan or Anjuli or Cassy dance to a beat, using all of their dance shapes

8) Make a sprite gradually grow in size and then shrink
Hint: make a size variable

9) Count down on a timer. A rocket takes off when you reach zero
Hint: Use the number icons in the letters folder

10) Add, multiply or subtract two variable numbers
Hint: Just to do addition only you will need 4 variables: firstNum, secondNum, answer (computer calculated) and myAnswer (human calculated)

In thinking about how to optimise, improve and extend this whole process I re-read some of my earlier posts about Scratch. This one is important in thinking about what the teacher ought to be doing beyond building skills:

playing with the kindergarten metaphor
imagine -> create -> play -> share -> reflect and then iterate again ...

Learning to share is harder than learning to ride a bicycle or write a computer program - but more important ...

Minsky quote: Logo has a great grammar but not much literature

It's important to explicitly promote reflection

I also expect that I will be using the excellent project ideas developed by a Mr. Michaud at Nebo Elementary School as a next step in a progression.


Wara said...

Hi Bill
I might be going about this in a way that is more complex that needed but I found the first challenge to be the most difficult and so I am going to put it last. I would be interested in talking about the solutions to this particular challenge.

Bill Kerr said...

hi wara,

You are correct but if you move the first challenge then move number two as well, since that requires some knowledge from the first one.

I'll mail you a copy of my solution. Note the trick, in 1a solution, of including the "if on edge bounce tile" after randomising the direction. This is more elegant and avoids the ball becoming tangled on the edge until it hits a random direction that moves it away. One of my students taught me this little trick

btw I didn't realise that you could embed working scratch projects in blogger but someone linked to my blog and there it is:
Room 402: Year 6: Scratch Challenge