In this article by Badov (2014), I found three simple activities that I would integrate in my lessons for students to learn encoding or decoding secret messages. The article link is in the reference list. All images are taken from the article.

1. Number coding: Students create a message using numbers to substitute the alphabetical letters.

2. Pigpen cipher: Students use images or symbols to represent letters. This allows students to have creativity in their learning.

3. Book cipher: Students will use a specific book and record the page number, line number and word position of each word they wish to use in their secret message.

Reference: Badov, C.A. (2014, May 12). 6 Secret Codes For Kids. Melissa and Doug. https://www.melissaanddoug.com/blogpost?postId=6-secret-codes-for-kids