Key Focus Points:

1. Understand what it is meat of hexadecimal
2. Be able to convert a number between number systems (i.e., binary, denary and hexadecimal)

Revision

In the last section, we discussed two different types of number system, in particular:

Denary (Base-10)

• Uses digits 0-9
• Natural for humans due to ten fingers
• Powers of 10 (1, 10, 100, 1000)
• Used in everyday calculations

Binary (Base-2)

• Uses only 0 and 1
• Natural for computers (ON/OFF states)
• Powers of 2 (1, 2, 4, 8, 16, etc)
• Used internally by computers

Can you still remember how to convert between these two?

In this section, we will look at another number system called hexadecimal.

Hexadecimal

Introduction

Hexadecimal (base-16) is a number system that uses 16 distinct symbols: the numbers 0-9 and the letters A-F. It serves as a bridge between binary and human-readable formats, making it particularly useful in computing.

We need hexadecimal because:

• Compact representation: It provides a more concise way to represent binary numbers. One hexadecimal digit represents four binary digits (bits)
• Memory addressing: It's commonly used in computer memory addresses as it's more readable than long strings of binary
• Color codes: Web developers use hexadecimal to represent colors in HTML/CSS (e.g., #FF0000 for red)
• Debugging: Programming tools often display data in hexadecimal format as it's easier to read than binary while still being closely related to how computers store information

For example, the binary number 1111 1111 can be written as FF in hexadecimal, making it much more manageable to work with.

Key Points