Flow of Activities
Activity Secret messages
How can you code a secret message?
Australian Curriculum Alignment
- Representation of data (ACTDIK008)
What's this about?
Encoding a word or phrase is an example of representing data in a different way.
The practice of encoding (enciphering, encrypting) and decoding (deciphering, decrypting) is called cryptography.
Two simple ways of encoding are the ‘backwards alphabet code’ and the 'shifted alphabet code’. They are easy to code but equally easy to decode ('crack').
Knowing the ‘key’ helps the decoder translate the message.
Learning tasks
- Write a simple message coded using a substitution of a number for each letter; for example, A=1 and Z=26. See how long it takes to ‘crack the code’ or ‘decipher the message’.
- Print out two columns containing the letters of the alphabet. Have one column in the correct order. But for the second, offset each letter by 2. For example, A would become C. Using this method, you can code words with each letter offset by 2. So ‘dog’ becomes ‘fqi’.
- Students work in a group of three. One student codes a message; for example, reverse the order so that A =26 and Z=1, or have A=1 +1, B=2 +1, Z=26 +1. The other two students decode the message. However, only one of these two students is given the rule. Discuss how the coding is like encrypting a message with a rule. The student without the rule tries different ways to crack the code (in the way a cyber-criminal might attempt to decipher an email that has been encrypted).
- Use a torch (switch it on or off) or hold up a black card and a white card, or use an electronics kit such as littleBits, to communicate a Yes/No answer to a series of written questions.
Supporting Resources
Assessment
Suggested approaches may include
- A list of words showing the encoded and decoded messages or words.
- Present a coded message and the students correctly decode the specific message.
Activity Braille
How are symbols used to represent text and other characters?
Australian Curriculum Alignment
- Representation of data (ACTDIK008)
What's this about?
Braille is a system for representing text and other characters using combinations of flat and raised dots so they can be read by touch.
One way to represent braille on paper without having to make raised dots is to draw a rectangle with 6 small circles in it, and to colour in only the circles that are 'raised'.
Braille is a representation using bits. That is, it contains two different values (raised and not raised) and contains sequences of these to represent different patterns. The letter m, for example, is represented vertically as:
11
00
10
where "1" means raised dot, and "0" means not raised dot.
Learning about braille is a good introduction to the binary system that uses 1's and 0's to represent data in a computer.
Learning tasks
- Discuss examples of where braille is seen in conjunction with other symbols or signage; for example, with lifts, toilets and public transport.
- Provide the alphabet represented in braille in picture. Discuss the rules of presenting text in braille. Look for patterns in the way the letters of the alphabet are represented. Create a representation of students’ names or familiar words in braille. Represent each letter as a rectangle with six circles either filled or not filled.
- As a game, students pair up and see who gets the most correct from a series of different braille letters.
- Have students try reading braille using their sense of touch, with text actually represented as raised dots. Discuss the challenges that visually impaired people might face in learning how to read braille.
Supporting Resources
Assessment
Suggested approaches may include
- A list of words represented using Braille.
Activity Morse code
How are symbols, sounds or light used to represent text characters?
Australian Curriculum Alignment
- Representation of data (ACTDIK008)
- Investigating and defining (ACTDIP010)
- Generating and designing (ACTDIP011)
- Evaluating (ACTDIP012)
What's this about?
Morse code represents the letters of the alphabet using dots and dashes. Every letter has a unique sequence of dots and dashes. Dots are created using a short pulse and dashes with a longer one. Morse code can be shown as symbols, sound or light.
Dots and dashes are used in combination to simplify the representation for each letter enabling each letter to be represented with a maximum of 4 symbols. Imagine if you just used dots you would need up to 26 dots to represent all the letters of the alphabet. That would slow down the sending of messages!
Learning tasks
- Provide the alphabet represented in Morse code.
- As a fun starter give students two minutes, to write ‘My name is_______’ where each letter is a dot corresponding to its place in the alphabet (a = *, b = **, c= ***), can they do that in the time frame? This will help embed understanding of why the dots and dashes exist as writing 26 dots for a z is impractical.
- Create messages and decode them in pairs. Discuss rules for creating and interpreting words for example, how will you identify a space between letters and a space between words?
- Use an online Morse code translator. Create the message in Morse code and translate. View the message as light or sound.
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This practical application will require 2–3 hours to complete. Use a programming board such as CodeBug or BBC micro:bit to create and send coded messages.
Students define the problem and design a digital solution for sending the message. For example, if using BBC micro:bit, create a simple code that uses ‘A’ button to create a dot and high pitched sound for ¼ beat and ‘B’ button for a dash with lower pitched sound and a beat of 1.
Have one student press the ‘A’ and ‘B’ buttons to send the coded message. The other person decodes the message heard and records the letters. Note: BBC micro:bit and CodeBug's online emulator plays the sounds, but, if you use the physical devices a buzzer would need to be connected using alligator clips.
Compare the original message to the decoded message. Discuss some limitations of this type of communication.
Students consider how this type of communication could be used to help someone at home, school or in the local community. How does this solution help these people?
Supporting Resources
Morse code translator
Use the Morse code generator/Decoder
Morse Typing Trainer
Use Google's Morse Typing Trainer to start learning how letters and words are represented in Morse code.
Morse Typing Trainer
Use Google's Morse Typing Trainer to start learning how letters and words are represented in Morse code.
Lesson Ideas
Morse code
This lesson is for a Codebug but can be also modified to suit BBC microbit.
Create a Morse code signal display with Circuit Playground Express
Here’s a more complex programming option for the use of a mini computer type programming board. In this example the program is for the Circuit Playground Express board with MakeCode, It is not expected students at Year 3 program at this level, however you may have some students who are looking for a challenge. Note if you have a BBC: Micro: bit or Code bug you could use the similar block to program.
Assessment
Suggested approaches may include
- A list of words represented using Morse Code.
- Demonstrating how to use BBC Microbit to send a message encoded using Morse Code and a partner decoding the message.
- List three different ways that braille could help a person or students provide a sample of their design (rules about letter representation).
Activity QR codes
How can we use a barcode-like image to link to information?
Australian Curriculum Alignment
- Representation of data (ACTDIK008)
What's this about?
A QR code is another way to represent data. QR stands for Quick Response. It is a scannable barcode-like image that directs you to a particular digital location set up by the code-creator. To read the code you need an app that reads QR codes and the camera on a smartphone or tablet device.
The barcode image is made up of pixels. Each pixel is made up of its own colour. In the case of QR code it is either black or white.
Learning tasks
- Create QR codes for the school veggie garden or garden or ‘smart’ garden providing information about plants, birds or insects that are of interest to students.
- Create an internet-based scavenger hunt. Devise clues linked to a QR code. Students use the QR code to locate the next clue. At each destination have students collect an item or a piece of information. Organise the activity so that it culminates in using the collected items or information to solve a simple problem. Integrate the use of directions (N, S, E, W) and measuring in steps or metres.
- Create a class quiz with small groups generating questions and linking their answers to a QR code.
- Bringing it all together
Create a display using the different forms of representing data. For example, the student could write their own name in the different forms so that it emphasizes the idea of the same data represented differently ie. name in English, name in code, name in braille, name in Morse code and name represented by a QR code.
Supporting Resources
QR Code Reader and Scanner
An easy-to-use App for QR Code and Barcode Reader.
Using QR Codes in the Classroom
Some inventive ideas for using the latest scanning technology for learning.
Assessment
Suggested approaches may include
- A QR code linked to information created by the QR code creator.