# Data Representation

**Topic List:
**

In this unit you will study the following topics in each lesson. Click the topic that your teacher wishes you to learn about:

**Binary numbers (3.1.1)****Binary arithmetic (3.1.4)****Negative and floating point numbers (3.1.2)****Hexadecimal numbers (3.1.5)****Representing text characters (3.2.1)****Representing bitmap images (3.2.2/3.2.4/3.3.2)****Representing analogue data (3.2.3/3.2.4/3.3.2)****Block assessment**

# Binary numbers

Learning Objectives Understand what a binary number is Understand why computers use binary instead of denary Learn how to convert a binary number to denary Learn how to convert a denary number to binary Learning Outcomes All must watch the video on binary numbers and have a basic idea of why computers use them. Answer binary […]

# Binary arithmetic

Learning Objectives Understand how to add binary numbers Understand how to subtract binary numbers Understand how to multiply binary numbers Understand the concept of overflow Learning Outcomes All must be able to complete (with lots of help) a variety of addition, subtraction and multiplication problems using binary numbers. Understand what overflow is and why it is important […]

# Signed Integers and Floating Point

Learning Objectives Learn two ways to represent negative numbers in binary (sign and magnitude and two’s compliment) Represent fractional numbers in binary. Learning Outcomes All must know the difference between signed and unsigned integers. Use at leaast one method to represent a fractional number. (Grade D/E) Most should Appreciate the difficulty of representing floating point numbers using binary digits. […]

# Bitmap images

Learning Objectives Understand how images can be represented on a computer. Appreciate the significance of depth/resolution. learn how a bitmap image works, and uses metadata. Learning Outcomes All must be able to complete simple pixel art, understand what a bitmap image is, and how a computer stores the information. Encode a simple image using binary. […]

# Representing analogue data

Learning Objectives Understand how an analogue signal can be stored in digital memory Understand how sound (as an example of analogue data) is stored on a computer Learning Outcomes All must use Audacity to explore how sample rate, bit size and compression have an effect on file size and sound quality. Answer the past paper […]

# Representing text characters

Learning Objectives Understand how characters can be represented by a binary code Understand the similarities and differences between two widely used character set systems – ASCII and Unicode Know how to work out the ASCII code for a given character Learning Outcomes All must read the page and look at the ASCII character set. Watch the videos. Fill […]

# Hexadecimal Numbers

Learning Objectives Understand what a hexadecimal number is Understand why hexadecimal is a useful number system Learn how to convert a binary number to hexadecimal (and back again) Learn how to convert a denary number to hexadecimal (and back again) Learning Outcomes All must watch the video on what hexadecimal numbers are. Use the HTML colour picker to see how […]