Workshop: Simulate computer

Draw a computer and look at computer components. Use children to simulate mouse, IO controller and a processor on the example of Calculator program. Before simulating the whole system, let kids get a feel of each individual component


White board or rectangular vertical surface, scissors, color paper, scotch, mouse pointer made of cardboard, crayons. Digits 0-9 and “+, -, =” cut out of color paper


I tried this presentation twice on a small group of kids 4-6 y.o. (5 people) and a large group (20 people). Also led this workshop to 3 classes of 1st graders in a public school.

For the small group I didn't need any preparation outside of stationary, for the large group I drew big numbers on color paper beforehand so that they can start cutting them out.

Every participant of computer simulation should have something that identifies him. 

Mouse: helmet (when users "click" on it)

Processor: big nerd glasses

Monitor (output controller): mouse pointer


Part 1. Draw a computer

If kids are small, draw a computer (mouse, keyboard, a box and a monitor). Tell them what the components are called and what they are for (e.g. The box contains the processor and does the most important job). Then ask the kids to draw a computer, make sure they can see your drawing. If the kids are self-sufficient ask them to draw a computer right in the beginning. You'll be surprised how attentive to the details some of them are. For example, most of them drew a scroll button on a mouse, which I wouldn't remember to put in there. For a large group distributing paper and crayons may take a lot of time, make sure you get help from other adults.

Skip this part altogether if you are pressured for time.

Part 2. Talk about what computer does

Ask kids what the computer is for, and what it can do. Acknowledge all ideas. Give an example of what it can do – add numbers – this is something very familiar with them.

Part 3. Calculator

At some point ask kids to cut out the big numbers from color paper – the digits in a calculator, including “+” and “=”. If the time is limited, make sure to have your numbers and operators ready.

Talk about the concept of a calculator – draw 10 big digits and +,-, = on a paper or use a white board and stick the cut out digits with scotch. This later will be a monitor. Give kids paper and ask them to record your actions and write down the answer. Then push the numbers on the calculator, e.g.

5, +, 3, =

Then the kids need to complete the equation. I skipped this part with the big group. For the small group the most interesting part is when the numbers are in double digits. It shows kids that consequitive digits define the same number. The kids in this age are used to thinking of a number as something whole, which doesn't have parts. For more advanced students, you may want to keep pressing digits and have them right down the huge number, then explain to them what this number is. Tell them that the computer can add even these huge numbers.

Part 4. Mouse

Choose a mouse-volunteer and a user. The user holds the mouse by shoulders and moves with it. Have the user move and the kids yell (“up” - forward, “down” - backward, “left” and “right”). Give a helmet to the mouse. Have the user press the helmet and have the mouse bend its knees, and kids will yell “Click”. Kids loved the helmet so much that they kept banging on it. As a result a mouse would even fall, which made teachers somewhat stressed out :)

After that tell the user where to move by yelling: “ up, down, left, right”

You may want other kids to try, depending on the group size and the time you have, but don't get dragged with this exercise, it's a lot of fun, but there is more fun ahead.

For advanced students, introduce a mouse controller: that person that watches the mouse movements and yells “up, down, left, right” or “click”

Part 5. Monitor, output controller

Choose a vertical rectangular surface as a monitor. A big screen tv works best, you can use white board or a table turned vertically. Attach digits and operators with scotch. This will be a monitor. Take out the mouse pointer and find a volunteer to move it.

Yell “Up, down, left, right” and make sure the volunteer moves the mouse pointer accordingly. Ask what digit the mouse pointer is pointing to. Ask kids to direct a volunteer to a specific digit.

Part 6. Putting it all together

Assign kids for the following roles:

  • User – moves mouse and clicks.

  • Mouse

  • Mouse controller – watches the mouse and yells “up, down, left, right, click” For a large group of kids, have them all do it, to be engaged

  • Output controller – moving a mouse cursor on the screen

  • Processor / Calculator program. - records equasion and produces the output (Part 3) Once the processor finishes computing it can write the resulting number and give it to bus. The bus will give it to the output controller who will display it on the screen. For a large group of kids, they all can count

  • Bus – once the mouse button is clicked, bus runs to the processor/program and tells it what was clicked. Once the processor finishes computing, it gives the result to the bus, which gives the result to the output controller. For a large group of kids bus is not needed for simplicity

If there are a lot of kids who are not being engaged, run the antiviruses – hide viruses around the class (whatever it may be) and assign antiviruses who run and look for viruses. Once a virus is found, it is brought to a processor who destroys it.

Part 7: Advanced


If it is not the first time the simulation is done, make it more complicated with interrupts. Have antiviruses run if the mouse is idle, once mouse controller detects a movement and yells “up, down, left, right, click”, the anitvirus programs freeze until the processor handles the request, and then they resume running.

leeping mode

If mouse controller doesn't detect any movements in a minute have it yell “Sleep”, and all computer components (except for the mouse controller) go to sleep. The user is not sleeping, if it moves the mouse again, the mouse controller yells “Wake up” and everything starts again.