Image 6. example blocks with pointed ends.
Run the program
I encourage you to use the information provided above along with the Scratch Programming Environment shown in Image 1 to write and run this program. Experiment with the code, making changes, and observing the results of yourchanges. Make certain that you can explain why your changes behave as they do.
A copy of this program has been posted online for your review.
I also encourage you to write the programs described below.
Student programming projects
The following projects are designed to:
- Help the student retain the knowledge gained by studying the module.
- Require the student to think beyond the material presented in the module by requiring the student to answer the question "How do I ...?"
Project 1
Begin with the program named Variable01 and modify it to create a new program named Variable02 . Modify the original program in such a way that pressing the space bar five times in succession, (after clicking the green flag to set both variables to zero) , will cause the displayed values of the variables named Counter and counter to be as shown in Image 7 .
Image 7. output from project 1.
Having reached that point, clicking the mouse five times in succession in the Stage area will cause the displayed values of the variables named Counter and counter to be as shown in Image 8 .
Image 8. output from project 1.
A copy of this program is posted online for your review.
Project 2
You should successfully complete Project 1 before attempting this project. Begin with the program named Variable01 and modify it to create a new program named Variable03 . Modify the original program in such a way that pressing the space bar five timesin succession, (after clicking the green flag to set both variables to zero) , will cause the displayed values of the variables named Counter and counter to be as shown in Image 9 .
Image 9. output from project 2.
Having reached that point, clicking the mouse five times in succession in the Stage area will cause the displayed values of the variables named Counter and counter to be as shown in Image 10 .
Image 10. output from project 2.
Hint: Compare the values of the variable named counter in Project 2 with the values of the variable named counter in Project 1 to determine what you need to do to successfully write Project 2 .
A copy of this program is posted online for your review (see Resources for the URL) .
Summary
I began by providing an overview of computer programming. Then I provided technical explanations for memory, variables, and literals.
I explained the meaning of the term algorithm.
I presented and explained a Scratch program that is designed to illustrate the creation and use of variables in a computer program. The Scratch programalso illustrates case sensitivity in variable names along with the ability to detect and respond to events fired by the keyboard and events fired by themouse.
Finally I presented two student programming projects that are designed to:
- Help the student retain the knowledge gained by studying the module.
- Require the student to think beyond the material presented in the module by requiring the student to answer the question "How do I ...?"
What's next?
In the next module, I will continue the process of helping you to learn about the following computer programming concepts using Scratch:
- Variables
- Expressions and Operators
- Sequence, Selection, and Loop Structures
Resources
- Scratch home
- Scratch download page
- Scratch tutorial - Dance Tutorial
- Scratch forums
- Son of String Art
- Scratch explanatory video
- Scratch tutorials from MIT
- Scratch tutorial - Digital Art for All
- Scratch for Budding Computer Scientists
- Learn Scratch at learnscratch.org
- Scratch Tutorial - Space Shuttle Mission STS-2020
- SCRATCH TUTORIALS ICT In Primary Education 2012-2013
- Scratch Wiki
- Scratch WikiTable of ContentsWebsite - Scratch Wiki
- Scratch WikiTable of ContentsTutorials - Scratch Wiki
- Scratch WikiTable of ContentsProgram - Scratch Wiki
- Tutorial about Variables - Scratch Wiki
- Scratch support MIT web site
- Scratch resources at Scratch.ie
- ScratchEd Resources
- Scratch project Day Dream
- Scratch project Son of String Art
- Scratch Project Scratch Tutorial
- Online version of program named Variable01
- Online version of student programming project named Variable02
- Online version of student programming project named Variable03
Miscellaneous
This section contains a variety of miscellaneous information.
- Module name: Scr0120: Memory, Variables, and Literals
- File: Scr0120.htm
- Published: 03/24/13
Financial : Although the Connexions site makes it possible for you to download a PDF file for thismodule at no charge, and also makes it possible for you to purchase a pre-printed version of the PDF file, you should beaware that some of the HTML elements in this module may not translate well into PDF.
I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version of the module.
In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale on Amazon.com showing me as the author. Ineither receive compensation for those sales nor do I know who does receive compensation. If you purchase such a book, please beaware that it is a copy of a module that is freely available on cnx.org and that it was made and published withoutmy prior knowledge.
Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.
-end-