Introduction to Computer Science

So you fancy doing Computer Science at GCSE level or even beyond? This taster lesson will introduce you to some of the areas and activities you might take part in. You may be introduced to this during a lesson and be asked to carry on with it outside. So be it!

Computer science as a subject was born out of the automation of mathematics. There are two branches of mathematics - continuous and discrete. Continuous mathematics deals with continuous data and calculus. Discrete mathematics deals only aspects of mathematics that do not employ the continuous method of calculus but instead, deal with discrete data. As computers are made from switches that can discretely be on or off, they are discrete mathematical machines. However, they can approximate solution to continuous equations much faster and more accurately than a human can ever do.


During a GCSE Computer Science course, you will learn about ...
  • Computer systems
  • Computing hardware
  • Software
  • Data representation
  • Databases
  • Communications and networking
  • Algorithms
  • Programming

So, who do you see yourself as?
As computer scientists, we create the technology that other people use. Would you rather be a mechanic or a driver?

Activity 1 Problem solving challenges

The main thing that Computer scientists do is solve problems. The problems might be easy to solve and take very little time or they may be hard to solve and take a lot longer. Some problems that Computer Scientists are faced with have never been solved!

Task Problem solving puzzles

Download the Starter Problems.docx worksheet and try to complete the problems by typing the answers on the worksheet. For some, you will need a calculator. How many can you do? Ask your teacher for the solutions when you have attempted them. You will be told whether you are right or wrong, but you won't be given the answer!

Did you persevere until you got the correct answer?
If you did, you might enjoy Computer Science!

ACTION : You should have a headache afterwards!




Activity 2 Communicating algorithms

Computer scientists develop algorithms. An algorithm is a step by step process for solving a problem. That could be a maths problem, a science problem or a spacial problem involving a robot. 

One way of communicating an algorithm is by drawing a flowchart.

Task Flowchart exercises

Visit the following website, read the introduction and attempt the exercises. Try to work quietly and independently until you get all the correct answers!

Did you easily work your way through all the examples?
If you did, you might enjoy Computer Science!

ACTION : Satisfaction!


Activity 3 Design the web

One of the marvels of the modern age is the World Wide Web. You probably use the World Wide Web every day. The web is a collection of interlinked files called webpages written in a markup language called HTML. Web developers design and author webpages.

Task Make it your own

An HTML file is a text file which you can edit with a text editor like Windows Notepad. When viewed in a web browser however, it blazes into action. The web browser interprets the HTML file which tells it how to display the content.


Read the following instructions carefully before you start ...

First, download the index.html file and save it into somewhere suitable in your user area. Find the file and open it with Notepad++ or Notepad. You might have to right click on the file and choose Notepad++ or 'Open with > Notepad' rather than double clicking on it. Choosing 'Run > Launch in Chrome' and your webpage should open in Google Chrome (if it's installed!), otherwise, choose 'Run > Launch in IE' will open the file in Internet Explorer.

Now try changing the HTML file to 'make it your own'! Alter aspects of the code, save the file, switch to the browser window and press the F5 key on your keyboard to refresh the page. Your teacher might demonstrate how to do this. You should try to ...
  • Changing the title
  • Adding three interesting facts about yourself
  • Changing the font
  • Changing the color (spelt wrong on purpose!)
Can you do this without any help?
If you enjoy this, you might enjoy Computer Science!

ACTION : Satisfaction!


Activity 4 Proper coding

Non-believers insist on calling HTML 'code'. In Computer Science terms, 'code' are instructions that help to solve a problem - HTML is simply markup which describes content and appearance.

Proper coding languages like Python and Javascript are very different.

Task Coding exercise

Visit the Codeskulptor website, delete the contents of the left hand panel and carefully type the following script ...

https://drive.google.com/file/d/0B83yXMOilskacW5QTl9xNV85bW8/view?usp=drive_web
Click to view larger

Can you get it to 'run'? Can you fix errors? The script works perfectly - you just have to type it in correctly!

Did you enjoy entering this code and getting it to run?
If you did, you might enjoy Computer Science!

ACTION : Satisfaction!


You have to be honest and decide whether ...
https://drive.google.com/file/d/1G2eM2DeDRQ-4WWzvoQWiZ9MiI-Z3isJW/view?usp=drive_web
Click to engage

If this is YOU, then maybe you should be choosing Computer Science as a GCSE!


Inspiration can be found in the most unlikely places


Activity 5 Pictures

Computers are also really good at storing data in different formats. One format that is used in computer systems is the bitmap image format which is used to store pictures as a series of tiny dots called pixels. Each pixel is assigned a special code which represents it's colour.

Task Bitmap studio

OK, so it's not Photoshop, but it's a start. Download the spreadsheet, Bitmap studio.xlsm, and experiment making your own bitmap image. You have to type the 'Code' into the 'pixels' to get it to change colour.


Did you enjoy designing your own bitmap image?
If you did, you might enjoy Computer Science!

ACTION : A beautiful bitmap image what you have created yourself. Be proud of your creative skills!

Still interested?
Speak to your Computer Science Teacher about opting for CS!


You, worn out because you've worked so hard!