Teach Computing

Revision notes, activities, lesson plans, teaching ideas, and other resources for GCSE, A-Level, and IB Computer Science teachers and students.

What's New

UK Computing Laws

This video from Computer Science Tutor covers the main UK computing laws re...

Wireless Networking (Wi-Fi, Security, and Hardware)

This video about wireless networking includes everything that is needed for...

Network topology videos

These four excellent videos from Computer Science tutor cover the four ma...

Network protocols

These four videos explain the main networking protocols that students are l...

Embedded Systems video

This short video is a good over of embedded systems, covering the main poin...

Representing Text in Binary

This video clearly explains the two main ways of representing text in binar...

Types of Malware

This video explains the various types of malware including viruses and troj...

Protecting against Malware

Following on from the Types of Malware video, this video explains technique...

Video: Network Security #1

This video gives an overview of the threats to networked computer systems, ...

Resources discount offer

2.2 Data representation

Click here for recommended Cambridge A-Level Computer Science textbooks.

2.2.1 Data Types

Unicode

Characters, Symbols and the Unicode Miracle

Characters, Symbols and the Unicode Miracle explains how ASCII arose from the need to communicate data in a compatible manner between computer systems, and the problems that arise with this apparently simple task. It then discusses the creation of the Unicode system.


Updated: 2015-04-29
Unicode character table

Unicode Table

Unicode table is a nice scrollable web page which lists all of the unicode characters. The title and a brief description of each section is presented while you scroll. This page is useful for helping students realise just how many different characters need to be represented by computer systems, and the problems this would cause with a standard like Unicode.


Updated: 2015-04-29

2.2.2 Arrays

Sorting algorithms

VisuAlgo: Sorting Algorithms

Visu Algo is another site which offers animated visualizations of common computing algorithms. The great thing about their animated sorting algorithms is the ability to display pseudo-code next to the animation and have it run step-by-step, following each line of code as it is processed. Really useful for helping students better understand code.


Updated: 2015-04-13
Algorithms

Algorithms in pseudocode and flow diagrams

This video from Cambridge GCSE Computing is an excellent introduction to algorithms, helping students understand what they are and how they are used. It also briefly introduces the idea of pseudo-code as a language for writing algorithms.


Updated: 2015-04-13
Merge sort and bubble sort

Bubble sort and Merge sort

Using a combination of playing cards and simple computer animations, this video clearly explains the bubble sort and merge sort algorithms step by step. It also compares the speed of each algorithm of data sets of different sizes.

The second half of the video examines the complexity of the algorithms, introducing 'Big O' notation and highlighting how bubble sort's complexity is a major drawback on large lists.


Updated: 2015-05-27
Sorting balance class activity

The Sorting Balance

This is another interactive to help students learn about sorting algorithms. They must use a set of virtual scales to test and compare the weights of 10 jars. Students must then line the jars up in the correct order at the bottom of the page. There are, of course, multiple ways to solve the problem - some more efficient than others. CS Field Guide have a similar game.


Updated: 2017-01-23
Animated sorting algorithms

Advanced ICT: Sorting algorithms

Another page with animated examples of various sorting algorithms, including bubble sort (standard and optimised versions), merge sort, and insertion sort. The animation speed can be increased or decreased to help visualise the process.


Updated: 2015-10-28
Bubble sort algorithm

Bubble Sort algorithm

This Bubble Sort video does exactly as its name suggests - explaining the algorithm clearing with the aid of diagrams. Although it is labelled as "Java", it is relevant to all computer science students.

There is also a good explanation of the algorithm (including why it is very inefficient) plus step by step diagrams here.


Updated: 2017-01-23

2.2.3 Files