Binary Lessons
Binary Representation of Characters
In this lesson, students will learn how characters are represented in a computer system.
Learning Objectives:
Curriculum Mapping
Learning Objectives:
- Explain the use of binary codes to represent characters
- Explain the term character set
- Describe with examples (for example ASCII and Unicode) the relationship between the number of bits per character in a character set and the number of characters which can be represented
Curriculum Mapping
KS3:
- Understand how data of various types (including text, sounds and pictures) can be represented and manipulated digitally, in the form of binary digits
COMPUTER SCIENCE EDUCATORS:
1a: Demonstrate knowledge of and proficiency in data representation and abstraction
- Effectively use primitive data types
- Demonstrate an understanding of static and dynamic data structures
- Effectively use, manipulate and explain various external data stores: various types (text, images, sound, etc.), various locations (local, server, cloud), etc.
- Effectively use modeling and simulation to solve real-world problems
CSTA K–12 CS Standards:
- 2-DA-07: Represent data using multiple encoding schemes.
- 3A-DA-09: Translate between different bit representations of real-world phenomena, such as characters, numbers, and images.
Lesson 1: Theory (Characters)
Suggested time: 50 mins
Starter:
Give students the attached worksheet (Starter.pdf) and ask them to complete the tasks.
Suggested time: 50 mins
Starter:
Give students the attached worksheet (Starter.pdf) and ask them to complete the tasks.

binary_code_breaker.pdf |
Starter answer sheet

binary_code_breaker_answers.pdf |
Main:
Explain that, in the previous lesson, the students have looked at how numbers are represented in a computer using binary. Also explain that characters are converted in the same way using something called a character set.
Inform students that one of the most commonly used character sets is ASCII (American Standard Code for Information Interchange) and show them the full 7-bit ascii table (See below).
Explain that, in the previous lesson, the students have looked at how numbers are represented in a computer using binary. Also explain that characters are converted in the same way using something called a character set.
Inform students that one of the most commonly used character sets is ASCII (American Standard Code for Information Interchange) and show them the full 7-bit ascii table (See below).

7-bit_ascii_table.pdf |
Explain that the ascii character set uses 7 bits which allows the computer to encode up to 128 characters.
Give students each a worksheet containing part of the ascii table (containing the letters A to Z in uppercase and lowercase) and ask the students to fill in the gaps in the table. Once complete, ask the students to attempt the challenges on the worksheet (see below).
Give students each a worksheet containing part of the ascii table (containing the letters A to Z in uppercase and lowercase) and ask the students to fill in the gaps in the table. Once complete, ask the students to attempt the challenges on the worksheet (see below).

ascii_secret_agent_challenge.pdf |
Answer sheet:

ascii_secret_agent_challenge_answers.pdf |
Plenary:
Option 1: Exit ticket
Ask students to complete the following statement:
“Today I learned ______________. One challenge I faced was ______________. Next time, I want to try ______________.”
Option 2: Binary games
Direct students to one of the following binary games:
Option 1: Exit ticket
Ask students to complete the following statement:
“Today I learned ______________. One challenge I faced was ______________. Next time, I want to try ______________.”
Option 2: Binary games
Direct students to one of the following binary games:
Support:
Share the following example if students are struggling with the task.
Share the following example if students are struggling with the task.
Binary to ASCII help sheet
You may be also interested in:
Tags: GCSE, KS4, Theory, Computing Theory, CS Theory, Binary, Binary Representation, binary 2, binary conversion, how to do binary conversion, counting binary, binary number to decimal, binary 101, 8 binary, binary digits, binary digit, meaning of binary