Some children may recognise that the 'code' is based on the values of the Scrabble tiles. Those values are based on the frequency of letters in written English and so this activity is a gentle introduction into the sort of data analysis which underpins much code breaking.
If this is your first code-related acivity you may wish to use the task 'What's in a name?' first.
Display the table or show this PowerPoint slide. Ask the children to write down their own name and work out what letters would represent it using the code. What do they notice?
Draw up an alphabet table on the board, and tell the children you are going to collate the letters from each child's name (using a five bar gate, or whatever way of recording is familiar to the children). Ask the children to predict what they think will happen.
Letter | Frequency |
A | |
B | |
C etc |
Once complete, compare their predictions with the actual table. Unless you have a lot of non-English names in your class, the frequency distribution is likely to mirror the Scrabble table.
If they haven't already spotted it, make connections to Scrabble and how the Scrabble values were derived. If you have a Scrabble set in the classroom, children could check that the table is correct.
Ask the children to add up the numbers in their names: whose name is worth the most/least?
Can they work out a short, high value name?
What about a long, low value name?
Let the children explore other sorts of words - can they make some short, high value words and some long, low value ones?
Which letters do you think will have the highest frequency?
Why?
Are long words always worth more than short ones? Why or why not?
If you have some Scrabble tiles they can be used to support children who need to manipulate the letters. You can download a set of blank alphabet tiles for children to make their own Scrabble set.
Use some of the texts familar to the children and ask them to analyse a short section to see if the frequencies are the same.
Here are some translations of the same text into other languages ( courtesy of Google Translate). How do these frequency tables compare?
In an English-language set the game contains 100 tiles, 98 of which are marked with a letter and a point value ranging from 1 to 10. The number of points of each lettered tile is based on the letter's frequency in standard English writing; commonly used letters such as E or O are worth one point, while less common letters score higher, with Q and Z each worth 10 points. The game also has two blank tiles that are unmarked and carry no point value. The blank tiles can be used as substitutes for any letter; once laid on the board, however, the choice is fixed. Other language sets use different letter set distributions with different point values.
Source: wikipedia