Representing text using Unicode and ASCII
Lesson details
Learning outcome
I can explain how computers represent text.
Key learning points
- The number of possible states of a sequence of n bits is 2 raised to the power of n.
- A character set is a ta record of characters matched to a unique binary sequence
- ASCII character representation use an 7 bit binary sequence to represent each character.
- Unicode character representation use up to 32 bits to represent each character.
- The first 128 characters of Unicode are the same as in ASCII.
Keywords
State - value of data at a specific point in time
Character set - a record of characters matched to a unique binary sequence
ASCII - a character set that represents each character with a unique numerical value
Unicode - a method of character representation that uses up to 32 bits per character
Common misconception
ASCII and Unicode are only used to represent the characters and symbols found in written communication across all languages in the world.
ASCII and Unicode include more than just characters from written languages. ASCII represents basic English letters, numbers, and symbols. Unicode supports a vast range of symbols beyond written text, including mathematical symbols and emojis.
Teacher tip
Use Python to explore the conversion of characters from character codes to the represented characters. Pupils could create secret ASCII messages to pass along for others to decode.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.How many bits are there in a byte?
Q2.What is the smallest unit of data in a computer?
Q3.Arrange the following in order of increasing bits:
Q4.What is the purpose of binary sequences in computers?
Q5.What is the next binary number after 111?
Q6.What is the binary equivalent of the decimal number 10?
Assessment exit quiz
6 Questions
Q1.Match the following terms to their definitions.
a method of character representation using 7 bits
a method of character representation using up to 32 bits
a record of characters, each matched to a unique binary sequence
smallest unit of data
8 bits together
Q2.How many different values can be represented by a 3-bit binary number?
Q3.If the ASCII value of 'A' is 65 in decimal, what is the ASCII value of 'C' in decimal?
Q4.Why might we need more than just ASCII for character representation?
Q5.How does Unicode differ from ASCII?
Q6.What is the relationship between ASCII and Unicode?
To help you plan your 10 computer science lesson on: Representing text using Unicode and ASCII, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 10 computer science lesson on: Representing text using Unicode and ASCII, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 computer science lessons from the Representation of text, images and sound unit, dive into the full secondary computer science curriculum, or learn more about lesson planning.