Last Updated on 08/14/2025 by Traci Hedetniemi
Every August 14, we observe a day of profound significance: National Navajo Code Talkers Day. This day honors the Native American soldiers who used their intricate and unwritten language to create an unbreakable code during World War II. This historical event not only showcases the elegance and power of codes, but also the ingenuity needed to both devise and decipher them. It stands as a powerful testament to how the adept use of patterns and language can solve complex problems. The foundational skills of pattern recognition and building codes, as demonstrated by the Code Talkers, remain just as crucial today in our digital world.
The Power of Codes and Patterns in Building Critical Thinking
Cryptography—the art of writing and solving codes—is at the heart of cybersecurity and data privacy, a relevant, real-world application for building students’ critical thinking skills. Understanding these ideas also helps us become more informed digital citizens.
The process of deciphering a code requires students to:
- Analyze information – Carefully examine coded messages and look for patterns.
- Formulate hypotheses – Make educated guesses about the type of cipher used and predict potential keys.
- Test and refine – The iterative process of trial and error; revising and trying new strategies when initial attempts do not work.
- Think abstractly – Consider the symbolic relationships between letters, numbers, and words.
Cryptography Ties to Mathematics
Writing and solving codes reinforce many mathematical standards:
- Patterns and Functions – Creating and recognizing patterns ties directly to algebra and the study of types of functions and function families. For example, a simple Caesar cipher is a linear function where each letter is shifted by a constant value.
- Statistics – Breaking substitution ciphers involves frequency analysis, which consists of counting how often letters appear in the coded message compared to their natural frequency in a language. For example, “e” is the most common letter in the English language.
- Matrices – More complex ciphers, such as the Hill cipher, use matrix operations for encryption and decoding. Matrix operations are often included in an Algebra 2 high school course and serve as a foundation for applications in linear algebra.
- Modular Arithmetic – Many ciphers, including the Caesar cipher, rely on modular arithmetic—a system of math based on the remainder when dividing by a modulus (think of this like the “wrap around” point for your counting system; on a clock, the modulus would be 12). High school-level math courses that include number theory may cover modular arithmetic.
Getting Started with Cryptography
Especially with younger learners, it may be helpful to start with a basic cipher —a simple coded message can become a puzzle or game. Try one of these two basic ciphers:
- Caesar Cipher – A shift cipher where the “rule” is simply to shift the alphabet by a certain number of places. For example, in a “+3 Key,” each letter is shifted three places, so the word CODE becomes FRGH. Students can learn more about the Caesar cipher and practice encrypting and deciphering messages in this interactive Crypto Corner resource.
- Pigpen Cipher – A symbol cipher where geometric symbols replace specific letters. Students can use this resource from Crypto Corner to learn more about and practice creating and decoding Pigpen ciphers.
The NavajoCode website is also a valuable resource for enhancing critical thinking skills; it features a series of posts that provide an excellent overview of cryptography.
Teachers interested in adding cryptography to class activities might think about using ciphers as locks in digital escape rooms. For example, a digital escape room created with Google Forms (reviewed here) could include an image with a “top secret” key (the cipher key) and a cipher that asks a question; students answer the question to unlock the room. Try using this Caesar Cipher Secret Message Maker from virtualescaperooms.org to create the locks! Alternatively, a simple no-tech option is to use the answers on a student worksheet as the code students need to decipher with a given key.
Elevating Coding Logic with Digital Tools
The resources below help students further cultivate critical thinking skills while extending their coding skills beyond ciphers into coding languages.
Elementary and Middle School – Foundational Coding Skills
- Scratch (reviewed here) is a free program developed by MIT that lets students code interactive stories, animations, and games through block-building. As they create, students learn how to build patterns through sequences of commands. Scratch is designed for students ages 8–16; younger learners (ages 5–7) can download the ScratchJr app to practice coding.
- Tynker (reviewed here) is another platform that uses visual coding blocks to teach programming. Teachers can access structured, interactive lessons and fun projects to support students in understanding how patterns form the basis of code.
High School – Advanced Coding Concepts
- Khan Academy (reviewed here) offers a free computer science theory course that includes a unit on cryptography. Lessons include both videos and practice exercises, offering a self-paced, asynchronous option to help advanced learners extend their understanding of coding, including ciphering and encryption.
- CryptoClub is a free website developed by a project team at the University of Chicago’s Center for STEM Education that offers cipher tools, games, daily crypto challenges, and comics that allow students to explore ciphers while reinforcing math skills. It also has a dedicated teacher resource page. Users who create an account can collect badges.
Teachers can find additional resources to support coding in TeachersFirst’s Help! I Lost My Library/Media Specialist article, Cracking the Code: Coding in the Classroom.
From the unbreakable code of the Navajo Code Talkers to the complex algorithms that secure our digital lives today, the power of patterns is undeniable. Using engaging digital tools to explore cryptography can elevate students’ critical thinking skills. The process of analyzing information, forming and testing hypotheses, and thinking abstractly develops essential skills for tomorrow’s problem solvers.
What are your favorite tools and strategies for teaching critical thinking skills? Share your ideas and successes in the comments below so we can learn together!