Problem A

Dated Messages

A *Caesar Cipher* is a way to create secret messages by
shifting letters in text. For example, a Caesar Cipher of \(3\) shifts each letter in the text by \(3\). If you want to shift the letter
**D** by \(3\), then you
count three letters forward to arrive at the letter **G**.
Similarly, if you want to shift the letter **E** by \(3\), then you count three letters forward
to arrive at the letter **H**. So in a Caesar Cipher of
\(3\), the letter **D** is
encoded with the letter **G**, the letter
**E** is encoded with the letter **H**, and so
on. When shifting letters, if you reach the end of the alphabet, you
continue counting at the letter **A**. For example, if you
want to shift the letter **Y** by \(3\), then you count forward to
**Z**, then to **A**, and end up at the letter
**B**.

Using a Caesar Cipher of \(3\), encode the message

**FRACTIONS**.To decode a secret message you shift the letters in the opposite direction. For example, in a Caesar Cipher of \(4\) the letter

**G**would be decoded as**C**.

Decode the message**AEXIVPSS**using a Caesar Cipher of \(4\).A

*Date Cipher*shifts the letters in a message by the corresponding digit of a date in the form*YYYYMMDD*. If the message is longer than the date, then we repeat the date as many times as necessary. In the table below, the message**FRACTIONS**has been encoded using the digits from the International Womenâ€™s Day, \(20240308\).Original Letter F R A C T I O N S Digit of Date \(2\) \(0\) \(2\) \(4\) \(0\) \(3\) \(0\) \(8\) \(2\) Encoded Letter H R C G T L O V U The secret message for

**FRACTIONS**would be**HRCGTLOVU**.A famous mathematician has the birthdate December \(9\), \(1906\) (\(19061209\)). Use the Date Cipher and this date to

**decode**the message**HAAIFJOYQNR**to find the name of the famous mathematician.

**Theme: **Computational Thinking