ECOSYSTEM: CRITICAL · KŌWHAI STREAM RESERVE: The system dashboard is flashing red. Water temperature has risen, algae cover has changed and fewer sensitive stream invertebrates are being recorded. Your mission is to trace the interactions, identify what is direct versus indirect, and recommend a response that fits the evidence.
ACTIVE OBJECTIVEECOSYSTEM: CRITICAL · KŌWHAI STREAM RESERVE: The system dashboard is flashing red. Water temperature has risen, algae cover has changed and fewer sensitive stream invertebrates are being recorded. Your mission is to trace the interactions, identify what is direct versus indirect, and recommend a response that fits the evidence.
WORLDSYSTEMS LAB
SEQUENCE01 / 08
REWARDGAME BREAK
BEFORE YOU START
Get set for this mission.
You can complete the essential lesson on this page. You do not need to print anything.
YOU NEED
Required: a device with this page open.
Optional: headphones for video or read-aloud.
Optional: pen + paper for rough working if that helps you think.
HOW TO DO IT
Read or listen to the Briefing + Learn.
Do the interactive mission.
Use the reading and maths/data evidence.
Make your decision and add the Project HQ step.
Play the weekly game if you want, then complete Check-in.
WORK YOUR WAY
Short bursts are fine. Use Learning Tools for easier reading, read-aloud, less on screen, stronger contrast, no-rush and quieter-screen options.
If a question feels hard, go back to the worked teaching, use the hint/feedback, and try one step at a time.
SCIENCE SAFETY: The science investigations in this Senior mission are designed as virtual/screen-based activities unless the page clearly says otherwise. Do not improvise mains electricity, heating or chemical experiments at home.
PROJECT NOTE: Your project can stay digital. Physical making is optional unless you choose that format.
MISSION BRIEFING
ECOSYSTEM: CRITICAL · KŌWHAI STREAM RESERVE: The system dashboard is flashing red. Water temperature has risen, algae cover has changed and fewer sensitive stream invertebrates are being recorded. Your mission is to trace the interactions, identify what is direct versus indirect, and recommend a response that fits the evidence.
✓Identify producers, consumers and decomposers in a simplified stream food web and explain how energy moves through the system.
✓Distinguish biotic factors from abiotic factors and explain how a change in one can affect several other parts of an ecosystem.
✓Use percentage change and comparative environmental data to identify a pattern without claiming the data proves a single cause.
✓Build a cause-and-effect chain that includes at least one indirect effect and one limitation or missing piece of evidence.
MISSION MEDIA · Crash Course Kids
Food Webs
Trace energy and feeding relationships before destabilising the stream food web.
Captions are controlled inside the YouTube player. If the embed is unavailable, use the YouTube link.
LEARN
CHANGE → DIRECT → INDIRECT → DATA → LIMIT
An ecosystem is a connected system, not a list of species. PRODUCERS capture energy, CONSUMERS obtain energy by eating other organisms, and DECOMPOSERS recycle matter from dead material. ABIOTIC factors such as temperature, light, water flow and dissolved oxygen can change the conditions organisms experience. When one part changes, effects can move through the food web. A useful investigation therefore asks CHANGE → DIRECT EFFECT → INDIRECT EFFECT → DATA → LIMIT. Correlation between two changes can be important evidence, but it does not by itself prove that one variable caused the other.
An ecosystem is a connected system, not a list of species. PRODUCERS capture energy, CONSUMERS obtain energy by eating other organisms, and DECOMPOSERS recycle matter from dead material. ABIOTIC factors such as temperature, light, water flow and dissolved oxygen can change the conditions organisms experience. When one part changes, effects can move through the food web. A useful investigation therefore asks CHANGE → DIRECT EFFECT → INDIRECT EFFECT → DATA → LIMIT. Correlation between two changes can be important evidence, but it does not by itself prove that one variable caused the other.
LEARNING BUILD
Refresh → Teach → Worked example → We do → You try
Build the idea before you enter the specialist lab. The point is to understand the reasoning, not just get through the buttons.
Topic knowledge:Food webs, producers/consumers/decomposers, biotic/abiotic factors, human pressures and ecosystem resilience.
This week’s first target:Identify producers, consumers and decomposers in a simplified stream food web and explain how energy moves through the system.
Quick evidence refresh: which source is a defensible starting point?
Choose a source that can directly support part of the investigation. More than one source may be useful, but start with evidence that does not outrun its support.
TEACH 1 · CORE MODEL
An ecosystem is a connected system, not a list of species. PRODUCERS capture energy, CONSUMERS obtain energy by eating other organisms, and DECOMPOSERS recycle matter from dead material. ABIOTIC factors such as temperature, light, water flow and dissolved oxygen can change the conditions organisms experience. When one part changes, effects can move through the food web. A useful investigation therefore asks CHANGE → DIRECT EFFECT → INDIRECT EFFECT → DATA → LIMIT. Correlation between two changes can be important evidence, but it does not by itself prove that one variable caused the other.
TEACH 2 · WHAT TO NOTICE
Identify producers, consumers and decomposers in a simplified stream food web and explain how energy moves through the system.Distinguish biotic factors from abiotic factors and explain how a change in one can affect several other parts of an ecosystem.
TEACH 3 · CONNECT + TRANSFER
Use percentage change and comparative environmental data to identify a pattern without claiming the data proves a single cause. Build a cause-and-effect chain that includes at least one indirect effect and one limitation or missing piece of evidence.
WORKED EXAMPLE · EVIDENCE
BASELINE · fictional stream data
Before the pressure event, the fictional monitoring record shows water temperature 16°C, dissolved oxygen 9.0 mg/L, algae cover 18% and a sensitive-invertebrate index of 72.
Reasoning: Start with exactly what the source establishes. Connect it to the relevant concept, then stop before the claim becomes broader than the evidence. Now compare it with OVERCLAIM: A fictional post says “warm water killed everything in the stream”. The monitoring record does not support that absolute claim and does not isolate temperature from the other changes.
Why caution still matters:This item is weak evidence for a broad conclusion: its claim or implication reaches beyond what the available support can establish.
WORKED EXAMPLE · MATHS / DATA ROUTE
The sensitive-invertebrate index falls from 72 to 54. What is the percentage decrease?
This week’s maths/data focus:Percentage change, comparative tables, graph interpretation and linked variables.
Name the variable or relationship, keep the units visible, calculate or compare, then interpret the result as evidence about the system. A result can support an explanation without proving every possible cause.
Worked solution:The decrease is 72 − 54 = 18. Compare that decrease with the original 72: 18 ÷ 72 × 100 = 25%.Answer check:25%. Now return the result to the question and state what it means in context.
WE DO · GUIDED PRACTICE
Which source needs the most caution before it is used to support a broad conclusion?
Choose any source whose claim outruns its support.
YOU TRY · INDEPENDENT PRACTICE
For Ecosystem: Critical, explain one core idea in your own words. Use one named source or observation from this page, then add one sentence saying what that evidence does NOT prove.
Write at least 18 words. Name the evidence or data you are using and keep the claim inside what it can support.
MISCONCEPTION CHECK
OVERCLAIM:A fictional post says “warm water killed everything in the stream”. The monitoring record does not support that absolute claim and does not isolate temperature from the other changes.
This item is weak evidence for a broad conclusion: its claim or implication reaches beyond what the available support can establish.
HELP
Try: “The system part/variable ___ changes ___. The evidence is ___. This suggests ___. One limit is ___.”
STRETCH · OPTIONAL
Add a second source, data point or test. Explain whether it strengthens, weakens or qualifies your first conclusion.
ECOSYSTEM CONTROL · KŌWHAI STREAM≋
ECOSYSTEM: CRITICAL
One dashboard. Many interacting parts.
Map the stream food web, separate biotic from abiotic indicators, test two fictional pressure events and decide what the evidence can responsibly support.
FICTIONAL MONITORING DASHBOARD
WATER TEMP16°Cbaseline
DISSOLVED O₂9.0 mg/Lbaseline
ALGAE COVER18%baseline
SENSITIVE INVERT INDEX72baseline
Run both fictional pressure scenarios. The values are teaching-model outputs, not predictions for a real stream.
Water temperatureDissolved oxygenAlgae coverSensitive invertebrates
DATA CHECK
The sensitive-invertebrate index falls from 72 to 54. What is the percentage decrease?
CAUSE-AND-EFFECT AUDIT
Which conclusion stays inside the evidence?
STABILISE + MONITOR
After an intervention, what gives the strongest evidence about whether the system is improving?
Run both pressure tests, solve all four food-web roles, classify all four factors, then pass the data, inference and monitoring checks.
OPEN THE SYSTEM EVIDENCE
SOURCE 1
BASELINE · fictional stream data
Before the pressure event, the fictional monitoring record shows water temperature 16°C, dissolved oxygen 9.0 mg/L, algae cover 18% and a sensitive-invertebrate index of 72.
SOURCE 2
AFTER CHANGE · fictional data
Four weeks later, temperature is 20°C, dissolved oxygen 6.5 mg/L, algae cover 42% and the sensitive-invertebrate index is 54. The variables changed together, but the table alone does not prove one single cause.
SOURCE 3
FOOD-WEB LINK
The model includes algae and aquatic plants as producers; grazing invertebrates as consumers; tuna/eels as predators; and microbes/fungi as decomposers. Real food webs are more complex than this simplified model.
SOURCE 4
HUMAN PRESSURE FILE
The fictional catchment log records reduced streamside shade and a nutrient-rich runoff event in the same month, so more than one pressure may be acting at once.
SOURCE 5
OVERCLAIM
A fictional post says “warm water killed everything in the stream”. The monitoring record does not support that absolute claim and does not isolate temperature from the other changes.
INVESTIGATE + ENGLISH · EVIDENCE CASE
When the dashboard moves, the whole system may be moving
Kōwhai Stream Reserve is a fictional monitoring site used for this investigation. Its baseline record shows cool water, relatively high dissolved oxygen, low algae cover and a higher index of sensitive stream invertebrates. Four weeks after streamside shade is reduced and a nutrient-rich runoff event is recorded, several indicators change. The water is warmer, dissolved oxygen is lower, algae cover is greater and the sensitive-invertebrate index falls. These patterns fit a system under pressure, but they do not prove that one factor caused every change. Shade, nutrients, flow, weather and interactions among organisms may all matter. Strong ecosystem reasoning traces plausible pathways while staying clear about what the data can and cannot establish.
MAKE THE CALL
Choose a response for the fictional stream: restore shade first, reduce nutrient inputs first, do both in a staged plan, or collect more evidence before acting. Use the system model and data to justify the choice, and name one result you would monitor to see whether the intervention is working.
BUILD YOUR CASE CONCLUSION1. Make the call. 2. Use at least two relevant pieces of evidence. 3. Explain one limitation or uncertainty. 4. Finish with what can responsibly be concluded.Strong structure: My judgement is… The strongest evidence is… However, we still do not know… Therefore…
CASE CONCLUSION: Write 180–240 words explaining what may be happening in the fictional Kōwhai Stream system. Use at least three evidence files, include the percentage change in the sensitive-invertebrate index, explain one direct effect and one indirect effect, and state one limitation or extra measurement you would want before claiming a single cause.
0/180 words minimum for this writing mission.
CLAIMEVIDENCELIMITATIONCONCLUSION
MATHS + DATA LAB
Check the numbers.
HOW TO SUCCEEDRead the situation first. Estimate what a sensible answer should look like, choose an efficient calculation, then use the feedback to check your reasoning.For data questions, explain what the number shows — and what it does not prove.
The sensitive-invertebrate index falls from 72 to 54. What is the percentage decrease?
Estimate first, then choose the answer.
MISSION 05 · MATHS + DATA LAB
DATA TRAINING
RATIO + RATE · YEAR 7 CORE
6 PROBLEMS
QUICK METHODRATIO + RATE
Find one part or one unit first, then scale up.
GUIDED · Q01–Q03Use the quick method, then check the explanation.
Q01
A 2:3 ratio has 10 in the first part. What is the second part?
2 parts become 10, so each part is 5. Three parts = 15.
Q02
180 km in 3 hours is what average speed?
Rate = distance ÷ time = 180 ÷ 3 = 60 km/h.
Q03
4 notebooks cost $12. Cost per notebook?
$12 ÷ 4 = $3 each.
INDEPENDENT · Q04
Scale 1:100 means 2 cm represents…
2 cm × 100 = 200 cm = 2 m.
INDEPENDENT · Q05
A recipe for 4 uses 300 g. For 8 people?
The number of people doubles, so the quantity doubles to 600 g.
INDEPENDENT · Q06
Which is the better unit rate?
$3 each is the lowest unit price.
OPTIONAL CHALLENGE · OPEN RESPONSE
Invent a ratio or unit-rate problem from everyday life and solve it.
0 words · optional
KEEP YOUR SKILLS SHARP
YOUR WEEKLY TRAINING
Four short sessions to spread across your week. Each has six problems and a reasoning mission. Allow about 10–15 minutes per session, and take longer when you need it.
Use paper for working. Enter numbers only; units are shown beside each answer. These are fictional practice scenarios.
0 / 24 correctSESSION 1 · NUMBER CHECK0 / 6
LEARN THE METHOD
Use brackets first, then powers, multiplication/division, and addition/subtraction. For fractions, use a common denominator.
WORKED EXAMPLE
18 + 4 × 3 = 18 + 12 = 30. But (18 + 4) × 3 = 66.
Use a hint
Multiply first: 6 × 3 = 18; add 89 to get 107.
Use a hint
Brackets first: 95 × 3 = 285.
Check the method after trying
6² = 36; subtract 3.
Check the method after trying
One quarter is 86; multiply by 3.
Check the method after trying
1/2 = 2/4, so 2/4 + 1/4 = 3/4 = 0.75.
Check the method after trying
(537 − 3) ÷ 6 = 89.
Compare your reasoning after trying
Multiplication is done before addition unless brackets change the order. For example, 2 + 3 × 4 = 14, but (2 + 3) × 4 = 20.
Your example may differ. Check your calculations and whether you explained why.
SESSION 2 · PERCENTAGE DETECTIVE0 / 6
LEARN THE METHOD
Percent means out of 100. Find a percentage of the whole by dividing by 100 and multiplying. For percentage increase, divide the increase by the original.
WORKED EXAMPLE
A count rises from 80 to 100: increase = 20; 20 ÷ 80 × 100 = 25%. The final count is 125% of the original.
Use a hint
25% = 1/4; 348 ÷ 4 = 87.
Use a hint
10% is 348; 5% is 174; add them.
%
Check the method after trying
348 ÷ 1740 × 100 = 20%.
%
Check the method after trying
Increase 348 ÷ original 1392 × 100 = 25%.
dollars
Check the method after trying
Discount = $174; subtract from $696.
people
Check the method after trying
Group counts: 348 + 696 = 1044.
Compare your reasoning after trying
Starting at 100 gives 120, then 20% of 120 is 24. The final count is 96 because the second percentage uses a different whole.
Your example may differ. Check your calculations and whether you explained why.
SESSION 3 · DATA INVESTIGATOR0 / 6
LEARN THE METHOD
Mean = total ÷ count. Median is the middle ordered value (average the middle pair if needed). Mode is most frequent. Range = maximum − minimum.
WORKED EXAMPLE
For 2, 4, 4, 6, 9: mean = 25 ÷ 5 = 5; median = 4; mode = 4; range = 9 − 2 = 7.
Use a hint
Total 376 ÷ 4 = 94.
Use a hint
Ordered: 91, 93, 94, 95, 100; take the middle.
Check the method after trying
99 − 89 = 10.
Check the method after trying
92 occurs three times.
Check the method after trying
Average the middle two: (93 + 97) ÷ 2 = 95.
Check the method after trying
Old total = 364; new total = 475; divide by 5.
Compare your reasoning after trying
A large outlier raises the total and mean. A larger sample can still be biased if it only includes one kind of respondent; selection matters as well as size.
Your example may differ. Check your calculations and whether you explained why.
SESSION 4 · CHANCE LAB0 / 6
LEARN THE METHOD
For equally likely outcomes, probability = favourable outcomes ÷ total outcomes. A probability of 0 is impossible and 1 is certain. Expected counts are predictions, not guarantees.
WORKED EXAMPLE
With 3 red and 7 blue counters, P(red) = 3/10 = 0.3. Over 50 draws with replacement, expect about 15 red, but actual results can vary.
Use a hint
3 out of 12 = 1/4 = 0.25.
Use a hint
3/4 = 0.75.
Check the method after trying
3/6 = 1/2 = 0.5.
Check the method after trying
Expected count = 712 × 1/2. This is not guaranteed.
Check the method after trying
Probability = 1/4; expected count = 356 ÷ 4.
Check the method after trying
There are no yellow counters, so this outcome is impossible.
Compare your reasoning after trying
No. Each independent flip still has probability 1/2 of heads. Earlier results do not force the next outcome.
Your example may differ. Check your calculations and whether you explained why.
Answers and reasoning save on this device when browser storage is available.
PROJECT HQ · TERM 3
PROJECT HQ · PROJECT FILE 03
PLAN — define success criteria.
Start something real. Build an idea, test it, improve it, and share it. Make your move.
PLAN your Resilient Systems Challenge. Define 2–3 observable success criteria for the system you chose, identify one weak point you want to investigate and name the evidence you would collect to tell whether an improvement works.
PROJECT HQ · PROJECT FILE 03
PLAN
Make your move.
PROJECT JOURNEYWEEK 3 / 9PLAN
Start something real. Build an idea, test it, improve it, and share it.
Turn your Resilient Systems Challenge into something that can be tested.
THIS WEEKPLAN
Complete only this project step today. Your saved work carries forward, so you do not need to finish the whole project at once.
A STRONG STEPSpecific · useful · achievable
Use evidence from this week's mission, name a real audience or purpose, and make the idea small enough to test and improve.
BEFORE YOU SAVE, CHECK:✓ I answered every field clearly✓ I used evidence or reasoning from this week✓ My next step is realistic
Complete each field with enough detail to carry this work into the next week. This step saves on this device as you type.
01BRIEF
02LEARN
03INVESTIGATE
05DECIDE
07PROJECT
08CHECK-IN