Students brainstorm and discuss the concept of cryptography, the science of secrets in today's world and then focus on a system for sending secret messages used by Julius Caesar. They make a Caesar wheel assessing encrypting and...

How many birthdays do leap year babies have in a lifetime? Learners explore the question among others in a lesson focused on different calendar systems. Given explanations of the Julian, Gregorian, and Martian calendars, individuals use...

In this recognizing time and timetables instructional activity, students compare Julian and Gregorian calendars, determine leap years, and apply the formula for finding the day of week and Easter day for any year. Students solve 20...

In this cryptography and cryptanalysis learning exercise, 8th graders read the explanation and example for codes and ciphers, then answer 2 questions and decipher 2 messages.

Students examine historical time and make time lines. They study the two main divisions of time; the time before and after the birth of Christ. They also note that time lines are a way of illustrating the length of historical time.

Students try to solve codes mathematically. The use of a code needs a key. Students try to decipher a code with a mathematical key. This requires focus and higher order thinking skills like analysis.

Julius Caesar encrypted messages two thousand years ago. By knowing the techniques of deciphering a code--frequency analysis, known text, and brute force--one can begin to understand the three key aspects of data encryption, decryption,...