How Computers Work


The purpose of this activity is to give the students a basic sense of how computers work by having them act out a simple computer simulation.

Each student takes on the role of a different part of a simplified computer and they work in groups to run a simple program. The end result of this program is to draw a picture on a simulated computer display.

It is designed for groups of 3 students, although it can be adapted to work as an individual activity or with groups of 2-4.


Ability to perform simple addition and plot (x, y) coordinates on a grid.

This activity is designed for students in grades K-8.


In this simulation of a (greatly simplified) computer, we consider a computer as being comprised of 3 major components:

We assign a student to each of these components and give them a simple program to run. The student acting as the CPU processes each instruction in order and tells the ALU/Memory and the Display what to do.

While the program is being run, the Display should hide the image so that the CPU and the ALU/Memory have no idea what it being drawn on the screen.

Once the program is done, the Display shows the result to the other members of the group.


Download all these PDFs in a single .zip file:

Display (PDF, SVG)
The student acting as the Display should use this worksheet to record what is being shown on the computer's display.

ALU/Memory (PDF, SVG)
The student acting as the ALU/Memory should use this worksheet to keep track of the current x and y values.

The student acting as the CPU takes one of the following programs and runs it by telling the ALU and the Display what they need to do.

Instructor Info (PDF, ODT)
Description and additional information for this activity.


Activity and documents created by Gary Kacmarcik. ©2007, 2010

These documents are licensed under a Creative Commons License Creative Commons Attribution-Share Alike 3.0 Unported License