Dr. Ashen's
activity page presents
Fun with
codes!
Hi kids! Dr. Ashen here with an exciting page of things to have fun with on a rainy day.
Do you know what a code is? It's a series of funny words which don't make any sense when you read them, but hide a secret message if you know how to look for it! Codes are used by spies and secret agents to send special messages to their bosses without the enemy finding out. After you've read this page, you'll be able to send secret messages to your friends without anyone else knowing what they mean. Are you ready to find out how? Then let's go!
Letter Substitution
This is easy. Do you know your alphabet? Great! That's all you
need to know for this code.
The alphabet has all the letters in a certain order - A,B,C,D,E
and so on. Instead of writing down the letter you want, you write
down the number of that letter in the alphabet. Here's an
example:
If we want to say:
I AM HAVING FUN WITH CODES
We would write:
9 - 1,13 - 8,1,22,9,14,7 - 6,21,14 - 23,9,20,8 - 3,15,4,5,19
Do you see? A=1, B=2, C=3, D=4 and so on. It's easy when you know how!
Now using this method, work
out the secret message below:
6,21,3,11,9,14,7 - 3,21,14,20 - 8,15,12,5
Did you get that? Fantastic! Let's try another type of code.
Alphabet shifting
This one is a little bit more difficult. Instead of replacing a
letter with a number, you replace it with a different letter. You
do this by writing down the letter that comes after the one you
want in the alphabet.
So if you wanted to say A, you would write down B. If you wanted
B, you would write C. All the person receiving your message has
to do is go backwards! (By the way, if you want to say Z, write
down A!)
Example - if we want to say:
CODES ARE COOL
We would write:
DPEFT BSF DNNM
All you need to do to
understand a message made using this code is go one letter back
in the alphabet. It's easy! Now try and work out this message
using what you've learned:
XBOLJOH TIJUGBDFE UXBU
Great stuff! Now you know all about secret codes. Now go and make up some codes of your own using the ideas I've shown you.
Have fun!