1. Introducing Variables to store information?
Phil Bagge
Code-it-co-uk

2. Variables
Programming languages, like Scratch, need a way to store information. They use a variable to do this. Variables are like containers, boxes or enverlopes.

3. Variables
Computers need a way to find the variable again. So all variables need a label like these labels on our containers.
toys
furniture
keys
labels

4. toys Inside a variable We call what is inside a variable the value
furniture
keys
2 chairs, 1 table, 1 sofa
1 teddy
3 keys
values

5. toys Reading a Variable
When a computer reads a variables label it displays what is inside.
toys
keys
furniture
2 chairs, 1 table, 1 sofa
1 teddy
3 keys

6. Say Hello var friendname how are you?
var is our way of showing that the next word is a variable
Say Hello var friendname how are you?
If a computer reads this it would display this
Hello Mike how are you?

7. Set var friendname to Mike Say Hello var friendname how are you?
var is our way of showing that the next word is a variable
Set var friendname to Mike Say Hello var friendname how are you?
Mike
Set puts the value into the variable
friendname
If a computer reads this it would display this
Hello Mike how are you?

8. If a computer reads this what would it display
If a computer reads this what would it display? Set var friendname to Milo Say Hello var friendname how are you?
Milo
Set puts the values into the variable
friendname

9. If a computer read this what would it say
If a computer read this what would it say? Set var friendname to Milo Say Hello var friendname how are you?
Milo
friendname
Hello Milo how are you?

10. If a computer read this what would it say
If a computer read this what would it say? Set var myage to 10 Say Hey, you are var myage. 10
myage

11. If a computer read this what would it say
If a computer read this what would it say? Set var myage to 10 Say Hey, you are var myage. 10
myage
Hey, you are 10.

12. Lisa
If a computer read this what would it say? Set var friendname to Lisa Say Hello var friendname how are you? I think var friendname is such a cool name. I wish I was called var friendname.
friendname

13. If a computer read the variable more than once what would it say
If a computer read the variable more than once what would it say? Set var friendname to Lisa Say Hello var friendname, how are you? I think var friendname is such a cool name. I wish I was called var friendname. Hello Lisa, how are you? I think Lisa is such a cool name. I wish I was called Lisa.
Lisa
friendname

14. Variable Fun
Create three variables with the following labels and your chosen values
Label
var bestfriend
var favnumber
var footballteam
Value
(you choose)

15. Take turns to read this message to your partner with the variables replaced with your values
Last night I ate var favnumber pies. I hate watching var footballteam on TV as they always lose by var favnumber goals. I am thinking of changing my name to var bestfriend because it sounds much better than my name. (No cheating read them exactly!)

16. Planning to use var name
Write some sentences that use a short name
Hello Bob good to see you. You are looking good Bob. I love what you have done with your hair Bob.

17. Planning to use var name
Replace Bob with var name
Hello var name good to see you. You are looking good var name. I love what you have done with your hair var name.

18. What is inside the variables?
If the user typed in Mark what would be inside var answer and var name?

19. 1 2 1 2

20. Work with your partner to examine this program
Can you work out how the author used a variable to personalise it?

21. Where might you use a name variable in your Maths quiz?
What words, phrases or questions would benefit from having someone's name included as well?
Discuss with your partner

22. Recap starter 1, Which block is the input block
2, What is the variable called?
3, Will anyone say the word travel after the method has been chosen?
Recap starter
travel
No they will say the value that is inside the variable not the label that we can see
Work in pairs
One person holds the card so that only they can see it.
The person holding the card asks the first question
The other person provides an answer
The person holding the card then acts out the rest of the program using the user input inside the variable