An IGCSE Computer Science Lesson — Told as a Story

🎙️ Once Upon a Flow...

In the pixelated kingdom of Techland, lived a brave and clever adventurer known as Captain Flowchart.

But Captain Flowchart didn’t sail ships or fight dragons. His job? Giving instructions to a team of robots who couldn’t read words or understand speech. The only thing they could follow were maps made of steps — pictures that told them what to do, one action at a time.

To help the robots complete their missions — like finding lost treasure or baking digital cookies — Captain Flowchart drew out all the steps in diagrams. These diagrams were called flowcharts.

🧠 What Is a Flowchart?

Just like a treasure map guides explorers to gold, a flowchart is a diagram that guides someone (or a computer!) through solving a problem step by step.

Think of it this way: 💡 An algorithm is a set of instructions. A flowchart is the picture of those instructions.

You’ve already followed algorithms in real life:

  • Making tea 🍵
  • Getting dressed 👕
  • Brushing your teeth 🪥
  • Playing a game 🎮

The difference? With flowcharts, we draw these steps using symbols — kind of like emoji for instructions!

🔣 Meet the Flowchart Symbols

In Techland, Captain Flowchart uses special shapes to represent different types of actions.

Here’s his toolkit:

🧩 Symbol 💬 Name ✨ Meaning
🔷 Oval Terminator Shows where the journey starts or ends
🔲 Rectangle Process An action like “pick up spoon” or “brush teeth”
🔷 Diamond Decision A yes/no question like “Is it raining?”
➡️ Arrow Flowline Tells the robot which step to go to next

Captain Flowchart says:

“If it’s shaped like a diamond, I’m making a decision. If it’s a rectangle, I’m doing something!”

☂️ Sample Mission: Should I Bring an Umbrella?

Let’s follow Captain Flowchart on a quick adventure.

Mission: Decide whether to bring an umbrella.

Flowchart logic:

  • Start

  • Is it raining?

    • If yes, bring an umbrella
    • If no, go outside without one
  • End

That’s it! A simple flowchart can solve everyday decisions.

✍🏽 Your Turn: Brush Like a Pro

Now let’s hand the map-making over to you, our young Techland explorers!

🎯 Challenge: Create a flowchart for brushing your teeth.

Suggested steps:

  • Start
  • Pick up toothbrush
  • Apply toothpaste
  • Brush for 2 minutes
  • Rinse mouth
  • Put toothbrush back
  • End

Try sketching it using the correct symbols. Think like Captain Flowchart — what shape goes where?

🔁 Bonus Challenge: The Vending Machine

Ready for a tougher quest?

Design a flowchart for a vending machine.

The machine should give you a drink only if you insert the correct amount of money.

What decisions would it make? What actions would it take? Can you make it smart and fair?

📘 Quick Quiz (Review Time!)

  1. What is the purpose of a flowchart?
  2. What shape do we use for a decision?
  3. Create a flowchart for making a cup of tea (from start to end).
  4. Why are flowcharts helpful before writing code?
  5. What’s one real-life thing you do every day that could be turned into a flowchart?
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