Scratch for intermediates course

1. Scratch for Intermediates
Matthew Parry
CAS Master Teacher
@becsalana
matthew.parry@computingatschool.org.uk

2. • Teaching
•Trained via GTP in Hampshire
•Shirland Primary School
•Swanwick School and Sports College
•Computing at School Master Teacher
• IT career
•15+ years as Programmer, Designer, Project Manager
•Civil Service, AA, Sony, Satellite TV red button
•COBOL, C, C++, VB, Java, Unix, PCs,
• Earlier
•Home: ZX81, ZX Spectrum
•School: BBC Model B

3. • To investigate advanced elements of Scratch
• To become familiar with some interfaces to
Scratch
• To plan how to use Scratch across the
curriculum
OBJECTIVES

4. • To make a timetables quiz ...
TASK

5. Broadcasts
Sends a message to all sprites and stage
But nothing happens unless sprite responds to the message
Green flag is a broadcast message
What is the difference between ...
and
Why use?
•To get other sprites to do something
•Reuse code
•Splits script into manageable parts
KS2 work with variables and various forms of input and output

6. Control Blocks
Forever Forever if <condition>
Repeat <#>
If <condition> If <condition> else
What difference do these make to your scripts?
Where would you use them?
KS2 …use sequence, selection, and repetition in programs ; use logical reasoning
to explain how some simple algorithms work

7. Control Blocks
Wait until <condition>
Repeat until <condition>
What about these? How do they differ?
Where would you use them?
KS2 …use sequence, selection, and repetition in programs ; use logical reasoning
to explain how some simple algorithms work

8. Control Blocks
Stop script
Stop all
Version 2.0
What different effects do these have?
Where would you use them?
KS2 …use logical reasoning to explain how some simple algorithms work

9. Variables
Variables
A named area of computer memory
A box that stores data
For something that can change (vary)
Variable for all sprites or Just for a sprite?
What difference does that make?
KS2 work with variables and various forms of input and output

10. Text Handling
Text
Task
Ask for users name.
Then ask five quiz questions. (Make some of answers numeric)
Keep score of correct answers.
At end display “<name>, you got <score> out of 5”
KS3 ... understand how data of various types (including text, sounds and pictures)
can be represented and manipulated digitally

11. Validation of Inputs
Validation
To ensure the input is what you want
Why?
Task
For quiz numeric answers make sure you get a number.
Ask for input again if not valid.
KS2 ... work with variables and various forms of input and output

12. Build Your Own Blocks
Build Your Own Blocks (Scratch 2.0 only)
Why?
To reuse code e.g. validation
What is a Parameter?
What is an Argument?
Task
Make number validation block
Pass in range parameters <lower> and <upper>
Extension: pass in number of digits expected

13. Variable Monitors
Normal Large
Slider
Max/Min
Where could you use each of these?
•For debugging
•As changeable text/numbers – e.g. Score
•To affect an application e.g. Sphere Maths
KS2 work with variables and various forms of input and output

14. Lists
Lists
A named area of computer memory
A series of boxes that stores data
For things that can change (vary)
For all or For sprite
Import list – text file from computer
Export list – output to computer
Examples: Haikus ...
KS2 ... work with variables and various forms of input and output
KS3 ... make appropriate use of data structures [for example, lists, tables or arrays]

15. Tips and Tricks - Help
Help
Website
http://scratch.mit.edu/help/
V1.4
Help Menu
Help Page...
Help Screens...
Right click on block
V2.0
Tips
 at right hand side of script area
Blocks
 ? at top of screen

16. Tips and Tricks - Comments
Comments
V1.4
Right click in background – “add comment”
Drag comment over block to attach
V2.0
Right click on block – “add comment”
Why use?
Gives clarity to script
Shows understanding
Assessment
KS2 ... use logical reasoning to explain how some simple algorithms work and to
detect and correct errors in algorithms and programs

17. Tips and Tricks – Sprite Control
Control a sprite
V1.4 – at top of sprite scripts
V2.0 – click next to sprite
What do those icons all do?
Run this script and click them as it runs
Watch x and y and direction ...
V1.4 padlock does same as
V2.0 “can drag in player”
What does blue line on sprite/circle do?

18. Tips and Tricks - Turbo
Turbo Mode
Speeds up all scripts
V1.4 via edit menu
V2.0 shift click on green flag
When would you use this?
When large scripts
Complex maths
Example - Art

19. Tips and Tricks - Debugging
Debugging
Single Stepping (V1.4 only)
See which block is being processed
KS1 ... create and debug simple programs
KS2 ... use logical reasoning to explain how some simple algorithms work and to
detect and correct errors in algorithms and programs

20. Tips and Tricks - Drawing
Perfect shapes (circles and squares)
When drawing hold down shift
Transparency
V1.4 – white and grey squares
V2.0 – red diagonal line

21. Tips and Tricks – Animated gifs
Animated gifs
V1.4
Drag gif onto costumes tab of an existing sprite
Or import gif onto costumes tab of an existing sprite
V2.0
Create new sprite using gif
New costume is created from each frame
http://heathersanimations.com/index.html

22. Need an account on http://scratch.mit.edu/ first
V1.4
Upload project to scratch website via Share menu
V2.0
Need to share project
Use “Embed” button below project to create html code
Cut and Paste into website
More information
V1.4
http://wiki.scratch.mit.edu/wiki/Embedding_Projects_(1.4)
V2.0
http://wiki.scratch.mit.edu/wiki/Embedding_Projects
Embed projects in own websites

23. Interfaces to Scratch
Lego Wedo - education.lego.com
Picoboards (Scratch 1.4) - www.sparkfun.com/products/10311
Kinect2Scratch (Scratch 1.4- scratch.saorog.com/
Scratcher Control for Android - khanning.com/scratchercontrol/
Makey Makey - makeymakey.com/

24. Resources
Scratch website/forums - scratch.mit.edu/
CAS website - http://community.computingatschool.org.uk/
Scratch website - Lesson Plans & Resources - scratch.ie/home
Derbyshire Computing Share Drive - goo.gl/ucNR17

25. BOOKS
Learn to Program with Scratch
by Majed Marji
ISBN: 9781593275433
Adventures in Raspberry PI
by Carrie Anne Philbin
ISBN: 9781118751251