Challenge type: Secret Codes · Difficulty: ★★☆☆☆ Easy · Code: Number code
This secret message is written in numbers instead of letters. Time to crack the code!
The secret message
3-1-20
How the code works
This is the A=1 number code. A is 1, B is 2, C is 3… all the way to Z, which is 26. Dashes go between letters, and slashes go between words.
Need a hint?
The first word of the answer has 3 letters and starts with C.
For teachers and grown-ups
Skills practised: Algorithms, encoding and decoding, and logical reasoning (cryptography basics).
The big idea: A cipher is an algorithm. Knowing the method and the key lets you undo it.
Questions to ask:
- What does the key (the shift) do?
- How could you crack a shift code without knowing the key?
- Why are simple codes like this not safe for real secrets?
Take it further: Make the paper code wheel from our printables and send messages between groups.