1 - Start ~4 mins
You have built games in Scratch and MakeCode Arcade. Today you look inside the machine that actually runs them. By the end of the lesson you will be able to name the main parts of a computer, say what each one does for your game, and sort what is hardware from what is software.
Open with a quick recap: students have already made games that run on the machines in front of them. Ask who can name any part inside a computer before you reveal anything. Keep this step short so the tour and the sort get their full time.
2 - How Your Game Gets Running ~6 mins
A computer is a machine that follows instructions. Hold these four chunks in mind; the tour and the sort will use each one in turn.
- Hardware and software. Hardware is the physical parts of the machine: the bits made of metal, plastic and silicon, whether you can see them or not. Software is the instructions and data. Your game is software.
- Storage and memory. When you open a saved game, it is copied from storage (where it sits when the power is off) into memory (where it sits while it is running).
- CPU. The CPU then carries out the instructions one after another.
- Input and output. Input devices such as the keyboard and mouse send signals in; output devices such as the screen and speakers send results out.
Walk the class through the layers diagram on the board before anyone touches a sort. Keep the full model visible for the whole lesson. Introduce the four chunks one at a time and pause after each: (1) hardware vs software, (2) storage vs memory, (3) CPU, (4) input/output. Anchor every layer in a game they already made: the Scratch or Arcade project file is software on storage; opening it loads a copy into memory; the CPU runs the blocks or code in order; the keyboard and screen are the input and output. Stress that hardware is physical even when it is sealed inside the case (CPU, RAM, hard drive). Common misconception: students often think the hard drive is where the game runs. Press the difference: storage keeps it when the machine is off; memory holds the live copy.
3 - Hands-on: Tour the Machine That Runs Your Game ~12 mins
Use the computer in front of you and one game you have already built as the running example. Work through the five stops below. Write in your copybook only where a stop asks for an answer.
- Outside the box. Name two input devices and two output devices you can see or touch on your machine. Which ones does your game use?
- Storage. Find your saved game file (class folder, signed-in account, or wherever your teacher has you save). That file is kept in storage when the power is off. On a PC that storage is often the hard drive; in an online account it sits on storage in a data centre.
- Open and run. Open your saved Scratch or Arcade game so it is ready to run. A copy is now in memory. Run the game for about thirty seconds. Every move and every score change is the CPU carrying out instructions from your game, in order.
- Storage and memory. Finish these two lines in your own words in your copybook (use the stems if they help):
- Storage is the part that keeps… when power is off
- Memory is the part that holds… while the game is running
- Make one change. Pick one tiny change, run the game once to check, then write what you changed and which hardware (input or output device) that change uses. Choose from:
- which key moves a sprite, or
- whether a sound plays
Before the lesson
Decide the recovery line if a student's saved game is missing: open any earlier project, or open a short sample game on the board so they still have a live example.
Predict beat (before stop 3)
Before anyone opens their game, ask: When you open the saved file, what do you think happens to it? Does it leave storage, or does a copy move somewhere else? Take two quick answers, then let them open and run it and check against the storage-to-memory path on the board.
Suggested timing
- Stops 1 to 2: about 3 minutes
- Stop 3 (open and run): about 3 minutes
- Stop 4 (two sentences on storage vs memory): about 2 minutes, then a quick board harvest
- Stop 5 (make one change): about 2 minutes
- Buffer and board harvest of CPU and hardware vs software: about 2 minutes
Teaching tips
Circulate and listen for the storage-versus-memory mix-up. If a student says the game runs from the hard drive, ask: What happens to the file when you switch the machine off? If they saved online, say: storage is still a drive somewhere, just not inside this PC. The hard drive card in the next activity is our classroom example of storage hardware. Keep the two copybook lines short; finishing the stems is enough. After stop 4, harvest two strong storage/memory lines on the board, then ask the class aloud (no extra writing): What does the CPU do with the live copy? and How is hardware different from software? Capture one strong answer for each on the board so CPU and hardware-vs-software are practised before the sort, without reloading every label as a write task. For stop 5, keep students on the two suggested options so edit time stays under three minutes. Push them to name the hardware (keyboard, speakers, monitor) not just the software edit. If edit access fails, let them describe one of the two changes and name the hardware it would use.
4 - Hands-on: Sort Hardware, Software and Jobs ~12 mins
Complete the interactive sort on screen.
- First, drag each card into Hardware (physical parts of the machine) or Software (instructions and data).
- Then complete the second sort by job: what holds your game when the power is off, what holds it while it is running, what carries out the instructions, what is input or output, and what is the software itself.
- Use the prompts at the end to check your thinking.
What is hardware, and what is software?
Run the sorts in challenge mode so students commit to a placement, then talk through wrong drops as a class. If you want pairs, decide that on the day; do not force it from the board. Watch for two sticky cards: the operating system (software, even though it feels like part of the machine) and RAM (hardware, even though you cannot usually see it). For the job sort, push students back to the layers diagram if they stall. If anyone argues that a cloud-saved game is not on the hard drive, agree: the hard drive card is the classroom example of storage hardware; online saves still live on storage, just in a data centre. Use the yourTurn prompts to lock in CPU and hardware-vs-software after the board harvest in the tour. End by asking one volunteer to explain the path: storage to memory to CPU.
The cards the activity supplies, and where each one goes
You do not need to make these; the activity provides them. This is the answer key so you can check the class without opening the activity yourself.
- The CPU → Hardware (physical parts of the machine)
- A stick of RAM → Hardware (physical parts of the machine)
- The hard drive → Hardware (physical parts of the machine)
- Your Scratch project file → Software (instructions and data)
- The Scratch editor in your browser → Software (instructions and data)
- The operating system → Software (instructions and data)
- The monitor → Hardware (physical parts of the machine)
- The keyboard → Hardware (physical parts of the machine)
5 - Make Sense ~3 mins
Your game is software. Storage keeps the file when the machine is off. Memory holds a live copy while the game is running. The CPU carries out the instructions in order. Input and output devices let you control the game and see the result. Hardware is the physical kit; software is the instructions and data.
Pull the class back for two minutes. Ask one student to retell the storage-memory-CPU path in one breath. If anyone still confuses memory with storage, put both words on the board with the power-off test: which one still has your game when you switch off? Optionally harvest one make-change example that names the hardware clearly.
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