Select a topic across a two year cycle

Recommended any combination of three topics per year.
Choose a combination of units that suits your students and context.

JAN DEC

Jan Jun Dec

Jan Jun Dec

Binary numbers

Overview

This unit introduces students to the binary system of ones and zeros used by digital technology to store and process numbers. They also learn how text, images and sound can be stored this way.

By the end of Year 8 students acquire, interpret and model data with spreadsheets and represent data with integers and binary.

• convert whole numbers between decimal and binary
• demonstrate how text, colour, images and sound are stored in binary form
• discuss why digital technology uses binary to process and store data.

The four sequences in this unit are designed to be covered in order.

Achievement standards

Digital Technologies: Years 7-8

By the end of Year 8 students acquire, interpret and model data with spreadsheets and represent data with integers and binary.

Use this work sample Binary explainer video that shows a student's response to the task: Create a video to explain binary for text, image and sound to a peer.

Use this work sample Designing and implementing a podcast for students to create a podcast where an interviewer and interviewee discuss counting in binary without visual aids.

Rubrics

Use these two rubrics to assess student skills, processes and knowledge.

Representing integers with binary

This rubric provides benchmarks for assessing different levels of complexity and proficiency in:

• counting up using binary bits (ones and zeros)
• converting positive, whole numbers between decimal (base-10) and binary (base-2) form
• describing why digital technology uses binary to store and process numbers.

Representing data with integers

This rubric provides benchmarks for assessing different levels of complexity and proficiency in:

• converting text into number codes using ASCII
• identifying RGB numbers for pixel colours in an image
• describing how sounds are sampled to produce a sequence of numbers.

Rubric: Representing integers with binary

1 (limited) 2 (basic) 3 (proficient) 4 (advanced)
Counting up using binary bits (ones and zeros) demonstrates understanding of binary one and zero representing their equivalents one and zero in decimal performs counting from zero up to at least 7 using binary bits performs counting from zero up to at least 7 using binary bits; shows understanding of the increasing number of bits required to reach larger numbers performs counting from zero up to at least 15 using binary bits; shows understanding of the increasing number of bits required to reach larger numbers
Converting positive, whole numbers between decimal (base-10) and binary (base-2) form demonstrates limited understanding of how to convert numbers between decimal and binary form using appropriate tools, consistently converts whole numbers between zero and 31 to binary form using appropriate tools, consistently converts whole numbers between zero and 31 to binary form; demonstrates understanding of place value in base-2 digits using appropriate tools, consistently converts whole numbers between zero and 127 to binary form; demonstrates understanding of place value in base-2 digits
Describing why digital technology uses binary to store and process numbers demonstrates limited understanding of why digital technology uses binary to store and process numbers demonstrates basic awareness that digital technology relies on off-on states for the storage and/or processing of data employs vague or abstract references to digital hardware to describe why it uses binary to store and process numbers employs clear references to digital hardware to describe why it uses binary to store and process numbers

Rubric: Representing data with integers

1 (limited) 2 (basic) 3 (proficient) 4 (advanced)
Converting text into number codes using ASCII demonstrates limited understanding of numerical ASCII codes representing text characters makes mostly correct conversions of text characters into numerical ASCII codes or their binary forms makes mostly correct conversions of text characters into numerical ASCII codes and their binary forms consistently makes correct conversions of text characters into numerical ASCII codes and their binary forms
Identifying RGB numbers for pixel colours in an image demonstrates limited understanding of how colours are represented digitally identifies correct red, green and blue numbers for RGB colours most of the time identifies correct red, green and blue numbers for RGB colours most of the time; demonstrates understanding of how number of bits affects available number of colours consistently identifies correct red, green and blue numbers for RGB colours; demonstrates understanding of how number of bits affects available number of colours
Describing how sounds are sampled to produce a sequence of numbers demonstrates limited understanding of how sounds are sampled to produce a sequence of numbers describes in basic terms the mapping of sound waveforms describes in basic terms the mapping of sound waveforms; demonstrates understanding of how the number of bits affects accuracy of digital sound uses appropriate vocabulary to describe the mapping of sound waveforms; demonstrates understanding of how bit rate and sample rate affect accuracy of digital sound

Unit sequence

Numbers to binary

The nature of digital systems means that they store and process numbers in binary form, as sequences of zeros and ones. Students can learn to convert whole numbers into binary via multiple paths: by recognising patterns when counting in binary, by creating a conversion table, by understanding binary as a base-2 number system, and by using digital tools to convert numbers back and forth.

Content description

Explain how and why digital systems represent integers in binary AC9TDI8K04

This sequence enables students to:

• count in binary
• convert whole numbers between decimal form and binary form
• discuss how the number of binary digits limits the size of values stored
• understand why digital systems store and process numbers in binary.

Text to binary

Since numbers are readily converted into binary form for computers to store and process, getting text into binary is achieved by expressing letters and other characters with numerical codes. Students can learn to use the ASCII system for encoding Latin letters and other characters this way, as well as exploring the much larger Unicode system.

Content description

Investigate how digital systems represent text, image and audio data using integers AC9TDI8K03

This sequence enables students to:

• express letters and other characters as numerical codes
• learn and apply ASCII codes
• explore the Unicode system
• make the connection from letters and characters to numbers, through to binary.

Images to binary

Since numbers are readily converted into binary form for computers to store and process, getting images into binary is achieved by representing them as sequences of numbers. Students can learn how each pixel in a raster image (like a photo) contains the numbers for its colour, while vector images (like clip art) are stored and drawn as geometrical paths.

Content description

Investigate how digital systems represent text, image and audio data using integers AC9TDI8K03

This sequence enables students to:

• understand and use the RGB system to represent any colour
• explain how raster images work
• explore how vector images work
• make the connection from images to numbers through to binary.

Sound to binary

Since numbers are readily converted into binary form for computers to store and process, getting sounds into binary is achieved by sampling their volume waveforms across time. Students can learn how this mapping is done, even visualising the sound waveform itself.

Content description

Investigate how digital systems represent text, image and audio data using integers AC9TDI8K03

This sequence enables students to:

• explore how sound is able to be mapped as a series of numbers
• practise using a digital audio editor to visualise waveforms
• make the connection from audio to numbers through to binary.