1. Number system
IGCSE Computer Science (0478)
  • Data Representation
    • Introduction
    • Why computers use binary (how binary represents data)
    • Number system
      • Introduction
      • Number Conversions
      • Addition of Binary Numbers
      • Logical binary shifts (positive 8-bit integers)
      • Two’s Complement (Signed: Positive and Negative Numbers)
      • Use of the Hexadecimal System
    • Text, Sound and Image
      • Text, Sound and Images
      • File Types
    • Data storage and File compression
      • Measurement of the Size of Computer Memories
      • Lossless and Lossy File Compression
  1. Number system

Use of the Hexadecimal System

Use of the Hexadecimal System#

What is Hexadecimal?#

Hexadecimal (or hex) is a base-16 number system.
It uses 16 digits: 0 to 9 and A to F.
A = 10, B = 11, C = 12, D = 13, E = 14, F = 15.
One hex digit can represent 4 binary bits (a nibble).

Why do we use Hexadecimal?#

1.
Shorter and easier to read than binary
Binary numbers are long and hard to read. Hex makes them shorter.
Example:
Binary: 1111 1010
Hex: FA
Much simpler!
2.
Used in programming and computers
Memory addresses are shown in hex.
Colours on websites use hex codes.
3.
Helps when working with large binary numbers
Grouping bits in 4s and converting to hex is easier than reading long binary strings.

Examples of Hexadecimal in real life#

Use CaseExampleMeaning
Colour codes#FF5733Red, Green, Blue colour values
MAC addresses00:1A:2B:3C:4D:5E (hex)Unique device IDs for network
IPv6 Addresses2001:0db8:85a3:0000:0000:8a2e:0370:7334Internet addresses
Error codes0x1A3FDebugging computer errors

Quick Practice#

1.
What is the hex code for binary 1010 1111?
(Answer: AF)
2.
Convert hex 1B to binary.
(Answer: 0001 1011)
Modified at 2025-08-11 06:30:50
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