# A.4.15.2 Caesar Says Shift

- Author:
- LeonMilewski

1. Now it’s your turn to write a secret code!
a. Write a short and friendly message with 3–4 words.
b. Pick a number from 1 to 10. Then, encode your message by shifting each letter that many steps forward or backward in the alphabet, wrapping around from Z to A as needed.
Consider using this table to create a key for your cipher.

c. Give your encoded message to a partner to decode. If requested, give the number you used. d. Decode the message from your partner. Ask for their number, if needed.

2. Suppose m and c each represent the position number of a letter in the alphabet, but m represents the letters in the original message and c the letters in your secret code.
a. Complete the table.

b. Use m and c to write an equation that can be used to encode an original message into your secret code. c. Use m and c write an equation that can be used to decode your secret code into the original message.