​Unit Learning Intentions 

 What you will learn: ​Units

1) bit, nibble, byte, kilobyte, megabyte, gigabyte, terabyte, petabyte

2) how data needs to be converted into a binary format to be processed by a computer.

3) data capacity and calculation of data capacity requirements

What you need to know?
  1. Why data must be stored in binary format 
  2. Familiarity with data units and moving between each
  3. Data storage devices have different fixed capacities
  4. Calculate required storage capacity for a given set of files
  5. Calculate file sizes of sound, images and text files
  6. sound file size = sample rate x duration (s) x bit depth
  7. image file size = colour depth x image height (px) x image width (px)
  8. text file size = bits per character x number of characters

What you will learn: Numbers

1) how   to  convert positive denary whole numbers to binary numbers (up to and including 8 bits) and vice versa

2) How to add two binary integers together (up to and including8 bits)

3) explain overflow errors which may occur ̈

4) how to convert positive denary whole numbers into 2-digit hexadecimal numbers and vice versa ̈ how to convert binary integers to their hexadecimal equivalents and vice versa perform a Binary shifts​
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What you need to know?
  1. Denary number range 0 – 255
  2. Hexadecimal range 00 – FF
  3. Binary number range 00000000 – 11111111
  4. Understanding of the terms ‘most significant bit’, and ‘least significant bit’
  5. Conversion of any number in these ranges to another number base
  6. Ability to deal with binary numbers containing between 1 and 8 bits e.g. 11010 is the same as 00011010
  7. Understand the effect of a binary shift (both left or right) on a number
  8. Carry out a binary shift (both left and right)

What you will learn: Characters
1) the use of binary codes to represent characters

2) the term ‘character-set’

3)the relationship between the number of bits per character in a character set and the number of characters which can be represented (for example ASCII, extended ASCII and Unicode).
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​What you need to know?
  1. How characters are represented in binary
  2. How the number of characters stored is limited by the bits available
  3. The differences between and impact of each character set
  4. Understand how character sets are logically ordered, e.g. the code for ‘B’ will be one more than the code for ‘A’
  5. Binary representation of ASCII in the exam will use 8 bits

What you will learn: Images
1) how an image is represented as a series of pixels represented in binary metadata included in the file

2) the effect of colour depth and resolution on the size of an image file, the quality of the mage, the size of an image file

​What you need to know?
  1. Each pixel has a specific colour, represented by a specific code
  2. The effect on image size and quality when changing colour depth and resolution
  3. Metadata stores additional image information (e.g. height, width, etc.)

What you will learn: Sound
1) how sound can be sampled and stored in digital form

2) how sampling intervals and other factors affect the size of a sound file and the quality of its playback

3) sample size, bit rate, sampling frequency.

4) the effect on playback quality and the size of a sound file

​What you need to know?
  1. Analogue sounds must be stored in binary
  2. Sample rate – measured in Hertz (Hz)
  3. Duration – how many seconds of audio the sound file contains
  4. Bit depth – number of bits available to store each sample (e.g. 16-bit)