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Pollution Calculations

Unit 9 · Week 4 · Maths in Environmental Context

SubjectScience / Mathematics
Year LevelYear 9–10
Duration45–60 min
CurriculumNature of Science · Mathematics
This lesson connects ← Week 4 Microplastic Sampling → Week 4 Traditional Water Assessment

Ngā Whāinga Akoranga · Learning Intentions

  • Apply rates, averages, and percentage change calculations to real pollution data
  • Interpret calculation results in their environmental context
  • Compare pollution levels across sites or time periods using quantitative evidence
  • Evaluate what the numbers mean for the health of a waterway or ecosystem

Paearu Angitu · Success Criteria

  • I can correctly calculate a rate (e.g. particles per litre, mg per day)
  • I can calculate a mean and a % change from pollution data
  • I can explain what each answer means in environmental terms
  • I can identify which site or time period has the highest pollution load based on my calculations

Hononga Marautanga · Curriculum Alignment

Mathematics — Statistics and Number

Apply proportional reasoning, rates, and percentage calculations in authentic contexts; interpret statistical findings.

Nature of Science — Communicating in Science

Use mathematical representations to communicate scientific findings; interpret data to draw evidence-based conclusions.

Raraunga Homai · Given Data

Use your data from the Week 4 Microplastic Sampling or NIWA Climate Data handouts, or use the teacher-provided dataset below.

Quantity / VariableValue(s)UnitsSource

Tatau 1 · Rate Calculation

Rate = Total quantity ÷ Time or Volume

e.g. Microplastics per litre = total particles ÷ litres sampled

Write your specific rate calculation here:

Tatau 2 · Mean and Site Comparison

Mean = sum of all values ÷ number of values

Add all your readings, then divide by how many readings you took.

Show your working:

Tatau 3 · Percentage Change

% change = (new value − old value) ÷ old value × 100

A positive % = increase in pollution. A negative % = improvement.

Show your working:

Whakamārama · Interpretation and Reflection

1. Summarise what your three calculations tell you about the health of this environment:

2. If you were presenting this data to a local iwi rūnanga or council, what would your key message be? (One sentence.)

3. What limitation in your data might weaken your argument? How could you address it?

Aronga Mātauranga Māori

Quantitative measurement of pollution — mg/L, particles/litre, % change — gives us precise, comparable evidence. But these numbers only matter when connected to the living systems they describe. In te ao Māori, the question is not only "how much pollution?" but "what does this mean for the wairua of this wai?" — for the mauri (life force) of the river, the awa, the moana.

Iwi and hapū use pollution data in resource consent hearings, Treaty settlements, and environmental monitoring partnerships with councils. The maths you practise here is the same maths used in real kaitiakitanga work. Numbers without context are inert; numbers in service of wai ora have power.

Ngā Rauemi Tautoko · Support Materials

Resources already provided:

  • Week 4 Microplastic Sampling handout — use your particle counts as input data
  • Week 4 NIWA Climate Data Analysis handout — use your recorded values
  • Calculator (permitted throughout)
  • Unit 9 formula reference card (distributed Week 1)

Aronga Rerekē · Differentiated Pathways

Tīmata · Entry Level

Complete Calculation 1 (rate) only. Answer interpretation question 1. Use a calculator for all working. Write your answer in a sentence.

Paerewa · On Level

Complete all three calculations. Answer all three interpretation questions. Show working for each calculation.

Tūāpae · Extension

Complete all sections. Design a fourth calculation of your own choosing (e.g. pollution load per km of waterway, projected level in 10 years using % change). Explain what your calculation shows and why it matters for environmental decision-making.