Digital system or not: sorting classroom objects

The idea

A digital system takes an input, follows instructions stored inside it and gives an output, so a tablet or a calculator is a digital system while a pencil, a wind-up timer or a torch with a plain on-off switch is not.

What you need

• 1 tablet or laptop, switched on
• 1 basic calculator
• 1 digital kitchen timer
• 1 wind-up (mechanical) kitchen timer
• 1 battery torch with a plain on-off slide switch and no light modes
• 1 pencil and 1 ruler
• 1 floor robot (for example a Bee-Bot) where the class has one
• 2 sorting hoops, one labelled with a picture of a screen and buttons, one with a picture of a hand tool
• Sticky notes and pencils for drawing inputs and outputs

How to do it

1. Sit in a circle. Hold up one object at a time and ask two questions: what do we do to it (the input) and what does it do back (the output)?
2. Press one button on each object that has buttons and watch closely: the calculator shows a number, the digital timer counts down and beeps, the floor robot moves the steps it was told.
3. Wind the mechanical timer and let it ring. Talk about what makes it ring: a spring inside, not stored instructions.
4. Slide the torch switch on and off several times. The torch does exactly the same thing every time and nothing inside it decides anything.
5. Place each object in a hoop: 'follows instructions inside it' or 'does not'. Each child explains one choice.
6. Draw one digital object and label one input (a button, a touch on the screen) and one output (the screen, a sound, the robot moving).

What you should see

The tablet, calculator, digital timer and floor robot go in the digital hoop; the pencil, ruler, wind-up timer and plain torch go in the other hoop. The learner knows the sort worked when they can name one input and one output for every digital object and can explain that the wind-up timer rings because of its spring, not because it follows instructions.

What changes

This activity lists no variables to change, measure and keep the same.

Common misconceptions

Each of these ideas is wrong, and the activity is a chance to test it.

• Anything that uses electricity is a digital system (a plain torch uses electricity but follows no instructions).
• A digital system must have a screen (a digital timer or a floor robot may have only buttons, lights and a beeper).
• Computers decide things for themselves (they follow instructions that people wrote).

Safety card

Curriculum references

The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.

• Science and Technology K–6 Syllabus (2017), NESA. The syllabus taught in 2026; the 2024 syllabus replaces it from 2027. Code read from the official syllabus document (DOCX) on 2026-09-22.STe-7DI-T
• Science and Technology K–6 Syllabus (2024), NESA. Implementation from 2027, so this code describes the future syllabus. Code read from the outcomes page on 2026-09-22.STE-DDT-01
• Australian Curriculum v9AC9TDIFK01

Sources

The pages the author read to write this activity.

1. www.nsw.gov.au/education-and-training/nesa/curriculum/science/science-and-technology-k-6-2017
2. curriculum.nsw.edu.au/learning-areas/science/science-and-technology-k-6-2024/outcomes
3. www.digitaltechnologieshub.edu.au/plan-and-prepare/scope-and-sequence-f-10/foundation
4. www.digitaltechnologieshub.edu.au/search/what-is-a-digital-system-and-how-do-digital-systems-help-us-years-f-2
5. www.digitaltechnologieshub.edu.au/media/barlbtay/f-2-hardware-and-software_unit-overview.pdf