How do Computers Work

Computer Science

CS is about more than just coding. It's about thinking and problem solving and how to use algorithms and computers to help us to solve problems.

Computer Science helps you get the big bucks.

Alan Turing is on the fifty pound note ($100).

https://www.theverge.com/2021/3/25/22349884/alan-turing-50-pound-note-design-uk-revealed

Alan Turing helped to win the WWII by defeating the Nazi Enigma codes. The film "The Imitation Game" paid tribute to him.

We will learn how computers work and how they encode data and decode information for users.

Binary

Activity 1)

Use the Binary Piano Flippy Sheet / Interactive to complete the Binary Worksheet.

Code.org Activity Guide - Flippy Do Pt 1 - Unit 1 Lesson 4

Binary Bracelet - encode letters

How Computers Work - Code.org video series

Data Representation of Images

Bitmap Art - a map of bits - Pixel Painting

Make Your Own a Spreadsheet of Pixels with Conditional Formatting

Activity 2) CS Field Guide Pixel Viewer

https://csfieldguide.org.nz/en/interactives/pixel-viewer/

Zoom in to look at the RGB of the pixels.

Click 'Toggle Menu' to upload your own image.

Click here to open the CS Field Guide Pixel Viewer

Make Your Own Google Sheet spreadsheet into a Grid

Add Conditional Formatting to change the Cell Colour based on the number, e.g.

  • 0 = black,

  • 1 = white.

If you want other colours you can add a key / legend for a range of colours, e.g.

  • 2 = red

  • 3 = green

  • 4 = blue


Code.org - Pixellation Widget - use Class Code: WZSCSF

There are 5 mini Lessons on the Pixellation Widget

Error Control - How Data Errors are Found & fixed

Parity Trick

Barcodes

Encryption & Hacking

Open these PDF in DocHub to Edit it (or write on the paper copy with a pencil!)

cryptography-resources.pdf

Caesar Cipher

In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. For example, with a left shift of 3, D would be replaced by A, E would become B, and so on. The method is named after Julius Caesar, who used it in his private correspondence. (text from: https://en.wikipedia.org/wiki/Caesar_cipher )

Activity 1)

Write a plain text message - encrypt it with https://csfieldguide.org.nz/en/interactives/caesar-cipher/

- send the message via email to a neighbour in class for them to decrypt.