Unit 3 Data Representation

Lesson 1 Introduction to binary

Learning Objectives:
  • Define the terms bit, nibble, byte, kilobyte, megabyte, gigabyte, terabyte
  • Understand that data needs to be converted into a binary format to be processed by a computer
  •  Convert positive denary whole numbers (0-255) into 8-bit binary numbers and vice versa


Textbook Ref:
  • binary data 144


Lesson 2 Binary, denary and hexadecimal

Learning Objectives:
  • Convert positive denary whole numbers (0-255) into 2-digit hexadecimal numbers and vice versa
  • Convert between binary and hexadecimal equivalents of the same number
  • Explain the use of hexadecimal numbers to represent binary numbers
  • Add two 8-bit binary integers and explain overflow errors which may occur


Textbook Ref:
  • binary data 144




Lesson 3 Representing characters and dates

Learning Objectives:
  • Understand how characters are represented in binary
  • Become familiar with ASCII and its limitations
  • Understand how dates are represented in binary
  • Understand what is meant by the terms data and information


Textbook Ref:
  • binary data 144




Lesson 4 Images

Learning Objectives:
  • Understand how a bitmap graphic is made up of individual pixels 
  • Explain how each pixel is represented in binary
  • Understand that the number of bits per pixel determines the number of available colours for an image
  • Explain the need for image metadata
  • Explain the relationship between file size and image resolution





Lesson 5 Sound

Learning Objectives:
  • Understand how sound is sampled and stored in digital form
  • Be able to represent a short sound file in binary
  • Explain how sampling intervals and resolution affect the size of a sound file
  • Explain the trade-off between file size and the quality of playback



Textbook Ref:
  • sound data files 145–147
  • speakers 120


Lesson 6 Assessment

Learning Objectives:

Students will
  • apply their knowledge in answers to a range of questions
  • be able to highlight areas of strength and any gaps in their understanding of computers



AQA Student Handbook Presentation