### 3. Teaching Computing

Sometimes I make teaching resources.

Here's a good place to share them. I hope you find them useful.

#### Recent posts

• Seven-Segment Simulator Here is my Seven-Segment Simulator.https://scratch.mit.edu/projects/29540696/ This is a Scratch project that allows pupils to explore the relationship between an array of binary switches ...
Posted 13 Mar 2017, 04:02 by Andy Lakin-Hall
• Simulations IntroductionComputer simulations can represent real or imaginary situations. They allow users to study or try things that would be difficult or impossible to do in real life.Simulations are ...
Posted 12 Jul 2014, 12:35 by Andy Lakin-Hall
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#### Seven-Segment Simulator

posted 13 Mar 2017, 03:59 by Andy Lakin-Hall   [ updated 13 Mar 2017, 04:02 ]

Here is my Seven-Segment Simulator.

This is a Scratch project that allows pupils to explore the relationship between an array of binary switches and a physically displayed number.

There is an accompanying activity sheet to guide the investigation. Pupils should try and work out the combination of switches required to display every number between 0 and 9.

As the switches are flipped, the decimal equivalent is shown top left. You will note that the decimal code for displaying a 7 is actually 7, but the decimal code for displaying an 8 isn’t 8. Challenge pupils to work out what’s happening with the decimal numbers.

Challenge pupils to discover any letter shapes that might be made with the 7-segment display.

## Why is this important?

Computer memory is made up of banks and banks of transistors, and each transistor is a switch.

Each switch can be either on or off – which gives just one bit (binary digit) of information. A single bit isn’t very useful, but if you arrange eight switches into a register, then you can store a whole byte of information – any number between 0 and 255.

The simulation shows how display hardware – in this case simple LEDs, can take a byte value and use it to represent a number or a letter.

Remembering RGB codes – any colour can be represented by three numbers; Red would be 255,0,0 and Yellow would be 255,255,0. So if your display was a screen of colour pixels, then each pixel needs three bytes to control its colour. My screen is 1280x1024, so that’s going to need 3,932,160 bytes of data, 50 times every second. You might grasp how much data a computer is handling as it works.

#### Simulations

posted 12 Jul 2014, 12:35 by Andy Lakin-Hall   [ updated 12 Jul 2014, 12:35 ]

## Introduction

Computer simulations can represent real or imaginary situations. They allow users to study or try things that would be difficult or impossible to do in real life.

Simulations are particularly useful when a real-life process...
• is too dangerous,
• takes to long,
• is too quick to study,
• is too expensive to create.

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