1. Lesson 4: Introduction to Hexadecimal
DATA REPRESENTATION
Lesson 4: Introduction to Hexadecimal
YEAR MIDHURST ROTHER COLLEGE

2. BRAIN CHALLENGE
Last lesson we looked at converting from denary to binary.
How would the following numbers be represented in binary?
EXTENSION: 4 7 15 43
103
126
154
163
215
248

3. DATA REPRESENTATION In this lesson you will...
UNDERSTAND what HEX is and why it is used.
LEARN how to convert numbers into hexadecimal and vice versa..
So that you can…
WRITE represent binary numbers in hexadecimal.

4. WHAT IS HEX?
In pairs, use the internet to search ‘hexadecimal’ and why it might be used in computing.
Find out what is hexadecimal.
Add what you find to your OneNote.
EXTENSION:
Find out how hexadecimal is used in computing.

5. DISCUSS: DIGITS Binary has 2 digits - 0 & 1.
Denary has 10 digits - 0, 1, 2, 3, 4, 5, 6, 7, 8 & 9.
Hex has 16 digits - How do we get higher than 9?

6. HEXADECIMAL DENARY 9 10 11 12 13 14 15 HEX A B C D E F
To count up to 15 (past 9) using hexadecimal we begin to use letters from the alphabet.
Remember to use these letters if you need to represent a number higher than 9!
E.g. We would 12 as C.
DENARY 9 10 11 12 13 14 15
HEX A B C D E F

7. CONVERT
HEX TO DENARY
In your OneNote, convert these hex numbers into denary numbers
9 6) 8B
B 7) AA
14 8) DC
1C 9) 156
2F 10) 2CF
256 16 1
NEED HELP?
Convert your letters to numbers. Multiply it by the value. Add them up to get the denary answer.
EXTENSION:
Find out how you would convert 8-bit binary into HEX. Add what you find to your OneNote.

8. HOMEWORK Computers need to convert everything to binary, even images.
Pictures are made up of tiny squares called pixels. Zoom right in and you will see them!
Each pixel's colour can be represented in binary or hex.
If a computer knows how many colours are used and how many bits are needed, it can convert the image to binary and back again.
20 pixels
16 pixels
YOU NEED TO:
Using up to 20 pixels by 20 pixels, design your own pixel art and add it to your OneNote.
20 x 16 = 320 pixels

9. PLENARY: FLIPPY BIT AND THE ATTACK OF THE HEXADECIMALS FROM BASE 16
Go to:
Defeat the aliens by converting hex into binary.
Who can get the highest score?