Codes have a lot of history attached to them. Secrecy and making sure the message got to the right person were essential and it is thought that even Stone Age people left coded messages for members of their tribes to identify where food or shelter may be found. It is believed that the famous pigpen cipher may have been developed in medieval times before becoming used more frequently in the 18th and 19th century by the Freemasons Society.
Activity One – Deciphering a code
LO: Be able to follow instructions to solve a logical puzzle
Use ciphers to decode a message
As with our activity in maths on codes and communication, code symbols require us to think in sequences and to remember certain facts.
The most common letter used in the English language is E
The most common three letter word is THE
The most common last letters are S and D
Single letter words are either A or I
Double letters followed by two single letters are almost always consonants
Double letters followed by a single letter are almost always vowels
A one letter word following a two letter word is usually an A
Consonants regularly alternate with vowels in a word
Give the children this numerical code which relates to the words underneath it
Ask them to use the rules you have for codes to see if they can decipher the message.
There are five of number 5, three of number 11, three of number 20, three of number 1, so the indication is that 5 must represent E
A one letter word follows a two letter word so it could be an A for number 1
Following the rules they will get most of the letters and will by a process of deduction be able to find the rest.
Now ask them to do the same with the pigpen code. Write out a message for them to decode using the pigpen cipher and ask them to apply the same rules.
At Home: Write out a coded message using the pigpen cipher and ask parents or guardians to decipher it.
Activity Two – Codes in History
The Enigma Code was one of the most famous and difficult codes to crack in World War Two. Ask the children to investigate how the code was discovered, how it was cracked and what the importance of it was.
The chronological nature of the event lends itself to the children producing a PowerPoint presentation on the code or as the episode has all the hallmarks of a great adventure, you could ask them to present it as a storyboard in cartoon format.
They will need to research the facts which are available on many websites or in books on the Second World War.
As an extension activity you can split the children up into opposing sides and ask each side to develop a code for passing messages. Once the code is ready, get the other team to try to decipher it with the team managing it first being the winners.
At Home: Ask the children to devise their own code for their friends in school to crack. Remind them that it should be logical and maintain the same code for each letter each time it’s used. Alternatively they could do a template code where, when the template is laid over an innocuous letter it reveals the words of a message.
Activity Three – Languages as Codes
LO: Understand that language is a form of code with a new word standing for the word they already know
Use language skills to make a code for others
One of the strangest code stories ever told was of the Navajo Code Talkers who used their native language in the Battle for the Pacific and specifically at Iwo Jima. The success of their work depended on them using what was effectively only a spoken language so the Japanese could not find a way to decipher what was being said. In such circumstances, the only way to crack the code is to capture and use a code talker or try to work out what was being said by the tone and structure of the conversation.
An idea of this can be gained from watching the following video where the actors speak in Greek
http://www.youtube.com/watch?v=S_qbMO28Ha0&feature=relmfu
Talking Point: Ask the children if they can guess what the actors are saying to each other
Tell the children they are going to pass a message spoken in a different language. Working in pairs, ask them to choose a language to use from Google Translate. Each pair should choose between three and five words and learn them together. To pass the code, one partner should say the words in random order and the other translate them in the correct order. They can start with three and move on to more as they get more confident.
As an extension activity, ask members of another pair to see if they can identify words that are being spoken. Where the language has similar roots to English this may prove easy. Explain to them that the reason Navajo was used by the code talkers was because it was very unlikely any Japanese person would have recognised it.
At Home: Ask the children to decode these messages written in different languages
Cati sedebat in grabattum
Köpek günlük oturdu
nguruwe alikuwa amevaa wig
Activity Four – Visual Communication
LO: Understand how words can be effectively represented by pictures
Be able to devise a visual code that can be used to transmit messages effectively
For millennia, humans have used a variety of means of visual, coded communication. Examples include Native American smoke signals, beacons and semaphore.
Ask the children to find out about a method of visual communication and why it was developed. They should prepare their work in a way that they can present it to the class, either reading from notes, using visual aids or as a PowerPoint presentation.
Ask them to include the following detail…
Which country and people used it?
Why was it developed?
How did it work?
What replaced it as a way of communicating?
Finally, if it’s feasible, ask them to give a demonstration to the class having given the class the code format. (Tongue in cheek warning! – Don’t try beacons or smoke signals in class!!)
At Home: Semaphore and Flag Signalling use colours and designs to represent letters. Ask the children to look at an example of how they work on this website: http://www.flaginstitute.org/pdfs/Barrie%20Kent.pdf
For homework, can they devise a colour and pattern code that works as well?
