Lesson Plan on Cryptology
University of Scranton
Education Department
Teacher – Shannon Robinson
School – ABC High School
Co-Operating Teacher – Dr. Scott Riley
Date – 1-10-13
Grade – 9th Grade
Class – Algebra
Lesson Plan Title – “Introduction to Cryptology: Why Do Men Dance?”
Lesson Objectives – Using The Adventure of the Dancing Men and a frequency analysis table based on the
English language, students will learn the basics of cryptology by decoding the some of the messages
present in the story.
State Standard(s) met – Seeing Structure in Expressions
• Interpret the structure of expressions
Sequence of Planning Strategies
Procedures, Directions, Notes and
Questions
Examples, Illustrations and
Resources
At the Bell: Students will be read the Computer, Smartboard or Projector
beginning of The Adventure of the
for illustrations of The Adventure of
Dancing Men to introduce them to the the Dancing Men.
(This lesson should take about
subject of cryptology.
fifteen minutes. The students in an
Handouts with the beginning part of
Algebra class will be introduced to The story will then be interrupted as
The Adventure of the Dancing Men
the topic of cryptology. Direct
students will be given a short two
for all students in case none of the
teaching and Cooperative teaching minute lecture on the definition of
above is working and so that each
will be used)
cryptology and will shown what a
student can have a copy of this
frequency analysis table is.
awesome story.
Introduction, Set Induction or
Anticipatory Set
Each student will be given a frequency Handouts of frequency analysis
analysis table.
tables for the class.
Lesson Content, Procedures
and Body
Cryptology – an all-inclusive term
The entire story will not be read given for the study of secret writing.
the interest of time but will be
summarized for the students as they go Frequency analysis table – shows
along.
the frequency of letters or groups of
letters in a given language. It is
Students will be shown an example of based on the idea that given any
a deciphered dancing men message by language, certain letters and
the teacher.
combinations of letters occur with
varying frequencies. For example, in
Students will be broken up into groups the English language, the letters E,
and will work, themselves, on trying T, A and O are the most common
to decipher the message behind the
letters. While, Z, Q and X are the
first dancing men appearance.
least common letters.
After students have worked on this for
a set period of time, students will
come out of their groups and as a class
see if they have determined the
messages.
Performance/Behavior
Standards
Students are expected to obey all
classroom rules including listening to
the teacher and not exhibiting
disruptive classroom behavior.
Students are expected to work quietly
at their desk when doing individual
work.
Each member of the group must be
participating and contributing to the
group discussion.
While working in groups, students
may get out of their seats and move
closer to one another if needed.
Closure
Students are expected to participate in
discussion as a class and while
Blackboard to show example of the
working in their groups by asking
deciphered dancing men message to
questions and actively listening and
the students.
responding to others.
Handouts with the dancing men
messages for each student.
Students will come back together as a
class where they will see if everyone
deciphered the first message correctly.
Students will then be given the rest of
dancing men messages and they can
work towards deciphering them for
homework for the next class when
they will come back to see if they are
correct in their cryptanalysis.
After doing this, the ending of The
Adventure of the Dancing Men will be
revealed to the students.
Assessment
Key information: The Adventure of
the Dancing Men is a great
introduction to the study of
cryptography. In it, a man named
Mr. Hilton Cubitt comes to visit
Sherlock Holmes and gives him a
piece of paper with a mysterious
sequence of stick figures in the form
of dancing men. These dancing men
seem to be upsetting his wife Elsie
who is noted to have had “very
disagreeable relations” in her youth
and began appearing after she
received a letter from the United
States, her home country. Mr. Cubitt
asks Holmes to figure out what
these mysterious figures represent
before it is too late. In response to
this, Holmes uses his deductive
skills to determine that these
dancing men are a substitution
cipher and performs a frequency
analysis based on letter frequency to
decipher the messages.
Students will not be strictly assessed
on this lesson as it is a fun activity.
Students should, however, put time
and effort into this activity.
Differentiation
Adaptions and modifications to the
lesson will be made as needed.
References
Doyle, A. C. (1997). The adventure
of the dancing men and other
sherlock holmes stories. Mineola,
NY: Dover Publications, Inc.
Cornell. (2004).
Frequency table. Retrieved from
http://www.math.cornell.edu/~
mec/2003-2004/cryptography/
subs/ frequencies.html