Keypad Spelling and Code breaking

Resource Info

Basic Information

Here is an interdisciplinary (Numbers & English spelling) game on creating and breaking number puzzles. Students will develop an appreciation for patterns, understand the basics of number patterns, and have fun using numbers to make and break simple codes.

00 hours 40 mins

Here is an activity for middle schoolers

  • Interdisciplinary (Numbers & English spelling)
  • Applicable to NCERT Grade VIII
  • Can be both learner-driven and teacher-assisted
  • Theme: Creating Number Puzzles & Games
  • Tools needed are dummy mobile keypad
  • Dictionary/Low end mobile phone
  • Appreciation for patterns
  • Understanding the basics of number patterns
  • Using numbers to code messages
  • Breaking and making simple codes
Activity Steps: 

How to Play?

Puzzles in the form are riddles are quite common. When puzzles are coded, it adds more fun to it.
For example, when A is coded as 1, B as 2, C as 3, the code for the word CAB is 312. The limitation of this way of coding can be understood when we convert CL into the number we get 312. There is no way we can ascertain whether the original 312 is CAB or CL, as the code for L is 12.

Here is a variation that helps come out of this limitation.

Take a print out of the dummy keyboard & distribute among the students whom you have grouped.


When we use a keypad version of assigning digits to letters, 2 can mean A, B or C and 9 can mean W, X, Y or Z. CUP, when coded this way it becomes 287 (as 2 stands for C, 8 stands for U and 7 stands for P). Interestingly, by the same coding, 287 also means BUS. The idea of trying out various combinations and then picking the meaningful word(s) helps them appreciate the art of coding. Let them guess the words that are number coded.

They are free to use  a dictionary.

An example,

If somebody gives you a numeric clue as 228, it means both CAT & BAT, the only condition being the string of alphabets should be meaningful words. (And hence any other combination of the alphabets that stand for 2 & 8 are invalid.)

Try solving what meaningful words are possible when the numeric clues are:


543 (more than 2 words are possible)



The level 2 for the game can be when one numeric clue has more than 3 answers!

For example,

Hint: The image is also a clue!

One more for you to try

And, the clue 7867 has more than 6 meaningful words. Take this challenge!

Last words:

The game so far is to predict the word(s). At the end of the class the learners are asked to think about the possible uses of the digits 1 & 0 for this game. (All answers are welcome)

Related links for the teacher:

Do Numbers Really Exist?
How a T9 dictionary in a mobile phone predicts the word.

It is a reworked resource from its 2014 avatar.

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