Science & Technology: Designing a Smart Water-Saving System

Outcomes:

• ST3-SCI-01: Explains how scientific knowledge is used to solve problems and inform decisions.
• ST3-DDT-01: Explains how digital systems represent and transmit data.
• ST3-DDT-02: Explains how digital systems process data to create solutions.

Learner: Adenetto, Stage 3 assumed

Weekly project: Adenetto will investigate water use, collect and represent data, then design and test a digital or analogue “smart” water-saving system.

Materials for the Whole Week

• Paper or a notebook
• Pencils, coloured pencils and ruler
• Sticky notes or small pieces of paper
• Calculator
• Measuring jug or cup
• Timer or stopwatch
• Two containers or buckets
• Cardboard, recycled containers, paper straws or craft sticks
• Tape, scissors and glue
• Coins, buttons or small blocks for counters
• Optional: computer or tablet with a spreadsheet or presentation program
• Optional: access to a tap, shower or watering can for observation only; do not waste water

Day 1: Science Helps Us Solve Problems

Goal: Adenetto will identify a real water-use problem and explain how scientific observations and evidence can help people make decisions.

Lesson steps — 50 minutes

1. Hook — “Where does the water go?” — 5 minutes

   Show Adenetto a measuring jug and ask: “How much water might be used while a tap runs for one minute? How could we find out rather than guess?” Record Adenetto’s prediction.

2. Show it: observe and measure — 10 minutes

   Demonstrate collecting water from a tap into a container for 10 seconds. Measure the amount. Explain that scientists make observations, measure carefully and record evidence. If using a tap is unsuitable, pour a known amount of water into a container and use it as a model.

3. Do it together: identify the problem — 15 minutes

   Discuss examples of water waste:

   • A tap is left running while someone brushes their teeth.
   • A garden is watered during the hottest part of the day.
   • A leaking tap drips all day.

   Choose one problem. Complete these sentences together:

   • “The problem is…”
   • “It matters because…”
   • “We need evidence about…”
   • “A possible solution could…”
4. Adenetto works independently: plan an investigation — 15 minutes

   Adenetto writes an investigation question, prediction and plan. Use this model:

   • Question: How much water can be saved by turning a tap off while brushing teeth?
   • Prediction: I predict that turning the tap off will save approximately ____ cups of water.
   • Plan: Measure water collected for 30 seconds with the tap running. Compare it with the small amount used to wet and rinse a toothbrush.
5. Brief recap — 5 minutes

   Ask: “Why is measuring more useful than guessing?” Reinforce that scientific knowledge and evidence can help people solve problems and make informed decisions.

Quick check

Adenetto completes: “Scientific evidence is useful because it helps us __________.” Expected response: understand what is happening, compare choices, solve problems or make informed decisions.

Day 2: Data Can Be Represented and Transmitted

Goal: Adenetto will collect water-use data and represent it in a table and graph, explaining that data can be represented in different ways and communicated to others.

Lesson steps — 50 minutes

1. Hook — “Can someone understand your measurements?” — 5 minutes

   Write these measurements on separate pieces of paper: 3 cups, 5 cups, 2 cups, 4 cups. Ask Adenetto what information is missing. Discuss the need for labels, units and an organised format.

2. Show it: make a data table — 10 minutes

   Model this table:

   Activity	Time or amount tested	Water measured
   Tap running	30 seconds	6 cups
   Tap turned off	30 seconds	1 cup

   Explain that the same information could also be represented with words, numbers, a picture, a table or a graph.

3. Do it together: collect data — 15 minutes

   Use the containers and measuring jug to test two situations safely. For example, pour water for 10 seconds into one container and 20 seconds into another. Measure each amount and repeat each test twice. Record the results. If water is limited, use dry counters as a model, with one counter representing one cup.

4. Adenetto works independently: create a graph — 15 minutes

   Adenetto makes a column graph from the results. The graph must include:

   • a title;
   • labels for both axes;
   • units;
   • an even scale;
   • a column for each test.

   Then Adenetto writes one sentence describing the pattern, such as: “The longer the tap runs, the more water is collected.”

5. Brief recap — 5 minutes

   Explain that when data is sent to another person, clear labels and a suitable representation help that person understand it correctly.

Quick check

Ask Adenetto to point to the graph’s title, scale and units, then answer: “What would happen if the scale were not labelled?” Expected response: The reader might not know what the numbers mean or could misunderstand the data.

Day 3: Digital Systems Process Data

Goal: Adenetto will describe how a digital system receives input, processes data and produces an output.

Lesson steps — 50 minutes

1. Hook — “How could a system know when to save water?” — 5 minutes

   Ask: “How could a device know that a plant needs water? How could it warn someone that a tap has been left on?” Collect ideas.

2. Show it: the input–process–output cycle — 10 minutes

   Use this example:

   Part	Example in a smart watering system
   Input	A sensor measures how wet the soil is.
   Process	The system compares the measurement with a programmed moisture level.
   Output	The system turns the water on, keeps it off or shows a warning.

   Explain that a digital system follows instructions to process data and create a useful result.

3. Do it together: act out a system — 15 minutes

   Use a button or sticky note as the input, Adenetto as the processor and a coloured card as the output. Use these rules:

   • If the “soil” card says DRY, show a blue card labelled WATER ON.
   • If the “soil” card says WET, show a red card labelled WATER OFF.

   Repeat the process with several cards. Discuss how the system uses data and rules to make a decision.

4. Adenetto works independently: write an algorithm — 15 minutes

   Adenetto writes numbered instructions for a water-saving alarm:

   1. Measure how long the tap has been running.
   2. Compare the time with the limit of 30 seconds.
   3. If the time is more than 30 seconds, sound an alarm.
   4. If the time is 30 seconds or less, do not sound the alarm.

   Adenetto changes the algorithm to include an extra output, such as a flashing light or a message.

5. Brief recap — 5 minutes

   Say: “Input, process, output.” Adenetto explains what each word means using the watering-system example.

Quick check

Give Adenetto this situation: “A sensor detects that the soil is dry, and a pump starts.” Ask for the input, process and output. Expected response: input—sensor detects dry soil; process—the system compares the reading with its programmed rule; output—the pump starts or water turns on.

Day 4: Design and Test a Water-Saving Solution

Goal: Adenetto will use scientific evidence and data-processing ideas to design, build and test a solution to the chosen water-use problem.

Lesson steps — 55 minutes

1. Hook — design challenge — 5 minutes

   Present the challenge: “Design a system that helps people use less water. It must receive information, follow a rule and produce a clear action or warning.”

2. Show it: examine a model — 10 minutes

   Sketch this example:

   • Input: a timer card showing how long the tap has been running;
   • Process: compare the time with 30 seconds;
   • Output: display “TURN TAP OFF” when the limit is reached.

   Explain that a good design has a clear purpose, uses evidence and can be tested.

3. Do it together: plan the design — 10 minutes

   Complete this design brief:

   • Problem: ______________________________
   • User: _________________________________
   • Input data: ____________________________
   • Rule for processing: If __________, then __________.
   • Output or action: ______________________
   • How success will be measured: __________
4. Adenetto builds a prototype — 20 minutes

   Adenetto uses cardboard, paper, counters and labels to build one of these prototypes:

   • a tap timer that gives a warning after a set number of counters;
   • a soil-moisture decision board with DRY and WET inputs;
   • a water-use data display that shows which activity uses more water.

   The prototype must show its input, processing rule and output. Adenetto labels each part.

5. Test and improve — 5 minutes

   Test the prototype with at least three different inputs. Record whether the output was correct. Make one improvement if the system is confusing, inaccurate or difficult to use.

6. Brief recap — 5 minutes

   Ask: “What evidence did you use to make your design decision?” Encourage Adenetto to refer to the data collected on Day 2.

Quick check

Adenetto points to each part of the prototype and explains:

• what information enters the system;
• what rule or process is used;
• what action or message comes out.

Day 5: Communicate, Evaluate and Improve the Solution

Goal: Adenetto will communicate how the solution works, use evidence to evaluate it and suggest an improvement.

Lesson steps — 55 minutes

1. Hook — “Would another person use it?” — 5 minutes

   Ask Adenetto: “If someone saw your prototype without an explanation, would they know what to do? What would make the design clear?”

2. Show it: model a design explanation — 10 minutes

   Read this example:

   My design is a tap timer. Its input is the number of seconds that the tap has been running. The system processes the information by comparing the time with 30 seconds. If the time is more than 30 seconds, the output is a “TURN TAP OFF” message. My test showed that the message appeared after 30 seconds. I would improve the design by adding a sound so that people notice the warning.

   Point out that the explanation includes the problem, input, process, output, evidence and improvement.

3. Do it together: evaluate the prototype — 15 minutes

   Use this evaluation table:

   Question	Evidence or example
   Did the design address the water-use problem?
   Was the input easy to identify?
   Did the rule process the information correctly?
   Was the output clear and useful?
   What could be improved?

4. Adenetto works independently: prepare and give a presentation — 15 minutes

   Adenetto prepares a short presentation using these sentence starters:

   • “The problem we investigated was…”
   • “Our evidence showed…”
   • “The input for our system is…”
   • “The system processes the data by…”
   • “The output is…”
   • “Our design is successful because…”
   • “One improvement would be…”

   Adenetto presents the prototype to the adult and demonstrates it with at least two different inputs.

5. Brief recap — 10 minutes

   Ask Adenetto to explain how scientific knowledge, data and digital systems worked together:

   “We used science to understand __________. We used data to __________. We used a system to process __________ and produce __________.”

Quick check

Adenetto answers these questions without looking at the notes:

1. How can scientific evidence help people solve a problem?
2. Give one way data can be represented.
3. What is the difference between an input and an output?
4. How does a digital system use a rule to process data?
5. What evidence shows whether the water-saving design worked?

Expected responses:

1. It helps people understand the problem, compare choices and make informed decisions.
2. Data can be represented as words, numbers, a table, picture or graph.
3. An input is information entering a system; an output is the action, message or result produced by the system.
4. The system compares the input with programmed instructions or a rule and produces the appropriate output.
5. Test results, measurements, observations or recorded data showing that the design produced the intended result.