How To Revise

Introduction

This revision zone looks at the ‘Hexadecimal Number System’.
Specifically:
– How the hexadecimal number system works
– The reasons why computer scientists may make use of this number system
– How to convert between binary and hexadecimal numbers

 

1: Read to Understand

Begin the revision process by reading the presentation…




2: Make some revision notes

Download the handouts pages and make your own notes about each slide.

3: Reinforce your understanding
Interactive Flash Cards

[qdeck align=”center” style=”width: 100%; border: 4px solid #306EFF;” card_back=”white”]
[h]

Hexadecimal Numbers

[q]What is a major drawback of writing binary numbers?
[a]One problem is that very quickly, a fairly small number like 258 (3 digits long) becomes the massive binary number of 100000010 (9 digits!)

[q]What is the hexadecimal number system?
[a]The hexadecimal number system is base 16. This means that its place values increase in the following manner:

Therefore the number 101 in hexadecimal is 257.

[q]Because the second column is 16, we have to count to 15 in the 1s column before we can place a 1 in the 16s column

…but in all number systems, placing two digits in one column is not allowed. How does the hexadecimal number system overcome this?
[a]The hexadecimal number system uses letters to represent 10, 11, 12, 13, 14 and 15.

[q]What is the hexadecimal number 13 in denary?
[a]

[q]What is the hexadecimal number 47 in denary?
[a]

[q]What is the hexadecimal number A1 in denary?
[a]

[q]What is the hexadecimal number AB in denary?
[a]

[q]What is the hexadecimal number 9D in denary?
[a]

[q]What is the denary number 50 converted into hexadecimal?
[a]

[q]What is the denary number 172 converted into hexadecimal?
[a]

[q]What is the denary number 101 converted into hexadecimal?
[a]

[q]What is the denary number 68 converted into hexadecimal?
[a]

[q]The question that many people ask is ‘why do computer scientists use hexadecimal?’
One reasons is that Hexadecimal uses fewer digits to represent values compared to binary – but so do denary numbers!?

So why do computer scientists use Hexadecimal?
[a]It is because it is easy to convert between Hex and Binary!

[q]How do you convert a binary number into hexadecimal?
[a]To convert binary into hexadecimal:
– split the number into nibbles
– work out value of each nibble (use A-F if value is 10-15)
– join the separate values to form the hexadecimal number.

[q]Convert the binary number 10000011 into hexadecimal?
[a]

[q]Convert the binary number 11111001 into hexadecimal?
[a]

[q]Convert the binary number 11010111 into hexadecimal?
[a]

[q]Convert the binary number 11101010 into hexadecimal?
[a]

[q]Convert the hexadecimal number BC into binary?
[a]

[q]Convert the hexadecimal number 4B into binary?
[a]

[q]Convert the hexadecimal number 2F into binary?
[a]

[q]Convert the hexadecimal number 7A into binary?
[a]

[/qdeck]

Printable Flash Cards



Download and print out these ‘Flash Cards’ – use them to reinforce your understanding!
Ensure you print these double sided, ‘flipped on short edge’ so that the front and back of each card match up!
 
The Hexadecimal Number System – 22 Flashcards

 
 
 

4: Assess your understanding
Assessment 1

Take the test to assess your knowledge and understanding of the hexadecimal number system.


 

Assessment 2

Take this test to assess your knowledge and understanding of hexadecimal and binary conversions.