1. Data Representation
N4/N5

2. Learning Intention Success Criteria Complete Task 1 - Unit Conversions
By the end of the lesson, you will
Understand how data is represented on a computer
Know the units used to measure storage capacity and file size
Be able to convert from one unit to another
Success Criteria
Complete Task 1 - Unit Conversions

3. What is a computer? Pros Cons
Definition - An electronic device for storing and processing data, according to instructions given to it in a program.
Pros
Fast
Accurate
Can store a huge amount of data
Never Forget
Video
Cons
Can’t think for themselves
No feeling
No common sense
A computer is a machine that carries out instructions given to it by a human. The instructions allow it to perform some useful functions as and when it is required. Without instructions (written by a programmer) a computer is a useless box of electronics that does nothing.
they do not have human style intelligence so can’t consider problems
This means that there are lots of everyday tasks that humans can perform that computers still cannot.
Pros: Show video “Fujitsu Motherboard Production”
Cons: Task. Identify three everyday activities that a human can perform but computers cannot (or are not very good at).

4. Data?
In computing, data is the term given to the numbers, text, graphics, sound & video that computers process.
In order to process data, it must be in a form that computers can understand:
BINARY
What is Data?
You have used software packages on a computer which handle text (word processing), numbers (spreadsheets) and graphics (photo editing and drawing). You may even have used packages which manipulate and store sound and video data.
In computing, data is the term given to the numbers, text, graphics, sound & video that computers process.

5. Binary
Computers work by switching circuits (transistors) on and off very quickly.
Computers are known as two-state machines, as a switch can only be on or off.
The numbers 1 and 0 are used to represent the on and off positions of the switches.
Each digit (1s or 0s) are called Bits (Short for Binary digITS)
Everything that the computer has to do and all the data that it works with and stores is represented using a two digit number system - 1’s and 0’s.

6. Units of Binary
When referring to memory and storage capacities, bytes became the basic unit of measurement. 1 Byte = 8 Bits
Unit
Description
Bit
It is the smallest unit which can be defined in a computer.
Bits (1s or 0s) correspond to simple switches being on or off.
Byte
A byte is a group of 8 bits
Kilobyte (Kb)
Exactly 1024 bytes Keep
Megabyte (Mb)
Exactly 1024 Kilobytes My
Gigabyte (Gb)
Exactly 1024 Megabytes Gold
Terabyte (Tb)
Exactly 1024 Gigabytes.
What’s next?
Petabyte, Exabyte, Zettabyte, Yottabyte…
Early computer worked with groups of 8 bits or a byte.
Today’s computers typically process groups of 64 bits (8 bytes) at a time.
Storage space: a few years ago we would not talk about TB for Hard Disk Drives…
Why 1024 and not 1000? Round number in binary (only 2 digits)

7. Changing From one Unit to Another
Using the appropriate unit is important
The traffic was dreadful last night. It took me 3300 seconds to drive home.
A high definition movie might require 1,717,986,918 bytes of storage space.
3300 seconds = 55 minutes
1,717,986,918 bytes = 1.6Gb
Do Task 1