7_2_11

WHAT: Understand how text can be represented and manipulated digitally in the form of Binary digits

HOW:

Activity 1 - READ

Every letter on your keyboard has a binary number associated with it. When a key is pressed an electrical signal is inputted for processing. To represent text, a character set is required. The simplest character set is called ASCII.

You can see a version of the ASCII Character Set on this website: http://www.asciitable.com/

Key facts about ASCII:

  • ASCII is a 7-bit character set
  • Each character uses 7 bits of data
  • The maximum number of characters possible for ASCII is 128

Why only 128??

Well, if you look at the table below then you can see the maximum number that can be created with a 7-bit binary digit.

| 64 | 32 | 16 | 8 | 4 | 2 | 1 |

| 1 | 1 | 1 | 1 | 1 | 1 | 1 | = 127

This means that there are 128 possible combinations of 1's and 0's if we include 0 as a number.

Activity 2

If you know that the binary representation of F is 1000110 then what do you think G might be?

Can you work it out?

Use the website in the link above to help you if you find this tricky.

Activity 3 - READ

ASCII is great if you are using standard English as a language but what happens when we need to communicate in other languages? Some languages have completely different characters to English. The Greek alphabet is a good example of this.

People all over the world communicate using digital devices so a different character set needed to be created. This is called Unicode. Unicode has a higher bit rate of 16 which allows for lots more combinations of 1's and 0's that caters for almost all of the languages in the world.

Activity 4

You can create secret messages using the binary representation of each letter. Try and write your name in binary as a practice. For example:

If your name was ANNA then you would find out the decimal number associated with the letters A and N. You can find this out here: http://www.asciitable.com/

A is 65

N is 78

In binary...

A is 1000001

N is 1001110

This means that ANNA in binary is...

1000001 1001110 1001110 1000001

Try it yourself with your own name!

CHECK:

EMBED:

Creating a Secret Treasure Map

Using graphics software, design a unique treasure map.

Note: If you don't have any graphics software then you can download one for free here: https://inkscape.org/en/

Don't put a path on your treasure map because this will make it too easy to solve!

When you are happy with your design, create some clues using binary digits. You could represent numbers as well as letters.

CLASSROOM IDEAS:

There are loads of ideas on CSUNPLUGGED to support this outcome. A good place to look is here: http://csunplugged.org/binary-numbers/