Resources by Nichola Wilkin Ltd

Data Representation: bitmap Images

Using a spreadsheet as a grid of 'pixels', this computing activity teachers how 1's and 0's can store image data. The classroom exercises use images with increasing pixel resolution, looking at how this affects the clarity of the image. Moving from black-and-white images, the students then use grids of colour...

History of computers

This classroom resource for secondary computing lessons outlines the history of development of computers. It covers thousands of years of history, including:

• the abacus
• log tables
• the calculators of Pascal and Leibnitz
• Jacquard looms
• Babbage's Difference Engine and...

Networks

This series of five one-hour lessons covers computer networks at secondary-school level. The objectives of the lessons are:

• Describe what a network is, the difference between a LAN and a WAN and identify three network topologies.
• Describe pieces of hardware that are needed in a network.
...

Python

This series of three lessons introduces Python programming to students in secondary school. The lesson objectives include:

• Creating simple code including the input and print scripts
• Using "If statements" to make a decision
• Using the random function in programs

Detailed...

Scratch

A ten-lesson sequence progressing from the basics of Scratch through to creating simple games. It includes:

• drawing shapes and using repeats
• accepting keyboard input to control the movement of sprites
• planning algorithms using flow diagrams and executing them in Scratch
• ...

Scratch Beginners

This unit of six lessons does not assume any prior programming knowledge and covers the following guidelines in the National Curriculum:

• Design - write and debug programs that accomplish specific goals, including controlling or simulating physical systems; solve problems by decomposing them into...

Session 2: Bitmap Images

In this session you will look at how images are made on computers using picture elements or, more commonly known as, pixels. If you have access to a computer you can follow the computer based activity. If you do not then you can follow the unplugged activity. Either way you will begin a journey into understanding...

Session 3: Saving Bitmaps

In this session you will look at image resolution and how to work out the size of a file. In real life the digital images we take are ever increasing in size. This session will help understand how the size of an image is calculated and also what an image actually looks like to a computer.

Session 4: Compression

In this session you will look at compressing files to reduce their size. You will see how both types of compression work and consider when they would be used.