Year 7 · Summer 1
Scratch II: Subroutines and lists · Lesson 4 of 5
Design a game with a flowchart before coding
TheoryTopic 11 Algorithms
Year 7 · Scratch II: Subroutines and lists · Lesson 4 of 5
You will learn to
- Identify the main flowchart shapes: start/stop, input/output, process and decision.
- Create a flowchart of the main loop of a game.
- Explain why planning on paper first saves time when coding.
Year 7 · Scratch II: Subroutines and lists · Lesson 4 of 5
Success criteria
You have got it when you can say:
- I can name and draw the main flowchart shapes.
- I can draw my game's main loop, with an arrow going back up.
- I can talk the teacher through my flowchart before I start coding.
Year 7 · Scratch II: Subroutines and lists · Lesson 4 of 5
Retrieval starter
Questions from before. Write your answers, then show them.
- Last lesson
Merge sort is fast on big lists. What's its main cost?
A It needs extra memory for the merged copiesB It needs the list to be sorted firstC It only works on numbers
A. It needs extra memory for the merged copies
- Last unit
x = input("Number: ") and the user types 5. What type is x?
A strB floatC int
A. str
- Earlier this year
Most of a smartphone's lifetime carbon footprint comes from…
A Recycling itB Making itC Charging it
B. Making it
Year 7 · Scratch II: Subroutines and lists · Lesson 4 of 5
Key words (1 of 2)
- Algorithm
- Precise, ordered, finite steps to solve a problem.
- Decomposition
- Breaking a problem into smaller ones.
- Abstraction
- Ignoring detail that doesn't matter for the problem.
- Sequence · selection · iteration
- Steps one after another. First this, then this.
Year 7 · Scratch II: Subroutines and lists · Lesson 4 of 5
Key words (2 of 2)
- Pseudocode
- Code-like writing for algorithms, without strict rules.
- Trace table
- Records variable values step by step to check logic.
- Variable
- A named place in memory that holds a value.
The explanation · step 1 of 1
Flowcharts
| Shape | Means |
|---|---|
| Rounded oval | Start / Stop |
| Parallelogram | Input or output |
| Rectangle | A process (do something) |
| Diamond | A yes/no decision |
| Rectangle with double sides | A subroutine |
| Arrow | What comes next |
A loop in a flowchart is an arrow going back up to an earlier step.
Year 7 · Scratch II: Subroutines and lists · Lesson 4 of 5
Quick quiz · 1 of 3
Which shape is used for OUTPUT total?
- A Diamond
- B Rectangle
- C Parallelogram
C. Parallelogram
Input and output are always parallelograms.
Year 7 · Scratch II: Subroutines and lists · Lesson 4 of 5
Quick quiz · 2 of 3
Breaking a problem into smaller parts is…
- A Iteration
- B Decomposition
- C Abstraction
B. Decomposition
De-compose = take apart.
Year 7 · Scratch II: Subroutines and lists · Lesson 4 of 5
Quick quiz · 3 of 3
An 'if… else…' is…
- A Selection
- B Sequence
- C Iteration
A. Selection
It selects one path.
Year 7 · Scratch II: Subroutines and lists · Lesson 4 of 5
Exit ticket
Answer on paper before you go. Then check.
In a flowchart, a decision is a…
A OvalB DiamondC Rectangle
B. Diamond Diamonds have yes/no arrows coming out.
The Tube map leaves out real distances. That's…
A AbstractionB Pattern recognitionC Decomposition
A. Abstraction Abstraction removes detail that doesn't matter for the problem.