Year 7 › Scratch I: Programming essentials › Lesson 2 of 5Year 7 · Spring 2 · Scratch I: Programming essentials Variables: score and lives Topic 13 Programming basics
KS3 Computing · A program stores information in variables, works on it with operators, and controls the order with sequence, selection and iteration. Examples are in Python, with Scratch alongside for Year 7.
Programming Cambridge Lower Secondary Computing 0860
You will learn to Explain what a variable is: a named box that holds one value at a time. Create a score variable that goes up by 1 each time the sprite is clicked. Use a lives variable that starts at 3 and counts down. Success criteria I can make a variable and show it on the stage. I can set the score to 0 when the green flag is clicked. I can make lives go down by 1 and say the value after each change.
variable A named place in memory that holds a value.
assignment Storing a value in a variable. = in Python, ← in pseudocode.
Casting Changing a value from one data type to another, like int("13").
Concatenation Joining strings together: "7" + "7" = "77".
Selection Choosing a path with if / else.
Iteration Repeating steps: a loop.
Boolean A value that is only True or False.
Infinite loop A loop whose condition never becomes false. Variables: labelled boxes A variable is a named box in memory that holds a value.
score = 0
score = score + 10
print(score) score = 0: make a box called score, put 0 in it. This is assignment .score = score + 10: read the right side first. 0 + 10 = 10. Put 10 back in the box.print(score) shows 10 .! Watch outIn code, = means 'store', not 'equals'. To ask if two things are equal, use ==.
e.g. ExampleScratch: the orange 'set score to 0' and 'change score by 10' blocks.
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