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Lesson Plan
Curated OER

Informational Writing: Business Letter

For Teachers 5th
Fifth graders write business letters. In this business letter instructional activity, 5th graders discuss the format and reasons for writing a business letter. They pick who they want to write to and create their own letter. 
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Lesson Plan
Curated OER

Grilling Algebra

For Teachers 7th - 11th
Students use a grille to investigate geometry. The application of the geometric figure, which is square, the students begin the coding of a message. The use of cryptography is used to reinforce algebraic ideas.
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Lesson Plan
Curated OER

Sieve of Eratosthenes

For Teachers 5th - 8th
Students discover the Sieve of Erathosthenes. They explore a method to find all the prime numbers in a group of numbers. Using models, students practice divisibility rules while examining the difference between prime and composite numbers.
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Lesson Plan
Shodor Education Foundation

Shodor Interactivate: Lesson: Clock Arithmetic and Cryptography

For Teachers 3rd - 8th Standards
This lesson plan is designed to guide students in practicing their basic arithmetic skills by learning about clock arithmetic and cryptography. Linked resources include helpful applets.
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eBook
Mathigon

Mathigon: Math Foundations: Divisibility and Primes: Real Life Applications

For Students 6th - 8th
This lesson provides real life applications for divisibility and prime numbers including the Cicada Cycle's use of prime numbers and Cryptography,encryption.
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Lesson Plan
Cuemath

Cuemath: Prime Factorization

For Students 5th - 8th
In this lesson, you will be learning prime factorization to solve various mathematical problems followed by solved examples and practice questions.
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Lesson Plan
Other

Curiosity in the Classroom: Principles of Encryption [Pdf]

For Teachers 9th - 10th
In a world where people are sharing information every second online, securing that information is paramount. In this lesson students will understand the principle of encryption, how to decode encryption, and how to construct ciphers. The...
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Article
Khan Academy

Khan Academy: Feedback

For Students 9th - 10th
Khan Academy is asking for feedback on lesson in cryptography.
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Unit Plan
TED Talks

Ted: Ted Ed: How to Organize, Add and Multiply Matrices

For Students 9th - 10th Standards
When you're working on a problem with lots of numbers, as in economics, cryptography or 3D graphics, it helps to organize those numbers into a grid, or matrix. Bill Shillito shows us how to work with matrices, with tips for adding,...
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Article
Khan Academy

Khan Academy: Xor Bitwise Operation

For Students 9th - 10th
If you've seen the lesson on the one-time pad, you know that it is the ultimate shift cipher. It involves the application of a random list of shifts equal to the length of the message. It's important to understand exactly how and why the...
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Lesson Plan
US National Archives

Nara: Teaching With Documents: The Zimmerman Telegram

For Teachers 9th - 10th
This is an excellent resource for anyone intersted in the Zimmermann Telegram: click to see the original coded message, the decoded message, and read about the implications of the telegram. This National Archives and Records...
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Activity
Texas Instruments

Texas Instruments: Numb3 Rs: Code Crackers

For Teachers 9th - 10th
Based off of the hit television show NUMB3RS, this lesson introduced students to simple methods of cryptography, most notably the Caesar cipher. By sliding the alphabet a certain number of spaces, students code and decode messages, and...