What Is the Hexadecimal Number System?

The hexadecimal number system is a number system that uses base 16.

This means it uses 16 symbols:

ValueSymbol0–9Same digits10A11B12C13D14E15F

Example:

2F (hexadecimal)

Hexadecimal is often used in computer science to represent binary numbers in a shorter and easier form.

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Why Computers Use Hexadecimal

Binary numbers can become very long and difficult for humans to read.

Example:

Binary
101011110010

Hexadecimal
AF2

Hexadecimal helps programmers and engineers work with binary data more easily.

It is commonly used in:

• Memory addresses

• Machine code

• HTML colour codes

• Debugging programs

Relationship Between Binary and Hexadecimal

Each hexadecimal digit represents 4 binary bits.

BinaryHexadecimal000000001100102001130100401015011060111710008100191010A1011B1100C1101D1110E1111F

Converting Binary to Hexadecimal

Example:

Convert

10101101

Step 1: Split into groups of 4 bits

1010 1101

Step 2: Convert each group

1010 = A
1101 = D

Answer:

AD

Converting Hexadecimal to Binary

Example:

Convert 3F

Step 1:

3 = 0011
F = 1111

Step 2:

Combine them:

00111111

Why Hexadecimal Is Important in Computer Science

Hexadecimal is widely used in:

• Programming

• Memory addressing

• Debugging software

• Networking systems

It provides a compact representation of binary values.

Exam Tip (2210 / 0478)

Students are often asked to:

• Convert binary to hexadecimal

• Convert hexadecimal to binary

• Convert denary to hexadecimal

These questions commonly appear in Paper 1 exams.

Practice Question

Convert 11101010 to hexadecimal.

Answer

1110 = E
1010 = A

Answer:

EA

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