Overview
This lesson introduces the binary number system. Students will compare and convert from a
base 10 (decimal) numbering system to a base 2 (binary) numbering system and
vice versa in the context of topics that are important to computer science. They
will learn how to convert letters of the alphabet to binary numbers.
Lesson Summary
● Students will review how to count using decimal numbers
● Change the base to 2 and try having students explain how it works
● Large Binary Card Demo (students in front of class)
● Binary Number Cards for each student to practice
● Virtual class field trip
● Have students preview Binary Clock and try to figure out how it works.
● Binary worksheets for extended practice
● Show students the Khan Academy Intro to Number Systems and Binary video from YouTube to help explain the difference in decimal and binary counting. (https://www.youtube.com/watch?v=ku4KOFQ-bB4)
● View the web resource to learn to convert letters of the alphabet to binary. (http://www.wikihow.com/Write-Capital-and-Lowercase-Letters-in-Binary)
● Students will write out their own short messages. Then they will exchange messages with an elbow partner. The elbow partner will decode the message. They will do this on notebook paper, and then check their accuracy using the
binary translator website.

CS Content
Students are learning the binary number system and its significance to computers. They will also learn how to convert decimal numbers and letters to binary.

Objectives
Students will be able to:
● Convert decimal numbers (and letters) to binary and vice versa
● Explain why binary numbers are important in computer science
● Encode/Decode a short message using binary

Materials and Prep
● Large Binary Cards
● Small Binary Cards
● Download Binary Clock

Overview
Provide a general overview the lesson. Include teaching tips here, if any.
The objective of this lesson is for students to be comfortable with the binary number system. They should be able to:
Count in Binary forward or backward
Connect Binary numbers to their function in computers

Lesson Summary
● Provide an overview of the various parts of the lesson (especially important if you suggest changing the lesson sequence)
● Then, list the lesson sequence. First activity - Second activity, etc.
I would introduce this lesson with 8 students(connecting that this is a byte of memory) each holding a card that has a one or a zero on it. The group will practice counting, flipping their cards over as they do it, while a student at the board will write down the decimal values (or point to them if they are written ahead of time).
Then I would have the decimal student write a challenge value and call on a student in the class to instruct the bits which ones should flip. This will help students to see that commands are sent to the computer and the computer responds.

Then I would introduce them to the Ascii table for characters and help them to see how each character is encoded…we would encode and decode messages.

CS Content
Provide a brief overview the CS content covered in this lesson. . Objectives
Students will be able to:
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Materials and Prep
● 8 cards with 1 or 0 on each side
● Paper for students to create their table quizzes w/solution and then one to give w/0 solutions
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Resources
Student Documents
● Statements to encode
● Asci table
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Code Studio
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Video
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Assessments
● Students would work in pairs create something to encode and then share it with someone else and check their solution.
● Students will write down 2 decimal numbers and their binary equivalent , From the message they encode and their two binary solutions they will create a table quiz to share, give it to another table and then correct the results.
● Challenge extension is to do an addition problem.
Notes

Binary number system, Acii code, memory, input, output.