• Quick retrieval from earlier learning (Decomposers and recycling nutrients; Energy transfer and pyramids). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. What do decomposers do? (hunt living animals / pollinate flowers / break down dead plants and animals / make food from sunlight) → break down dead plants and animalsPrompt: What happens to a fallen leaf over a few months?
2. Producers in a field capture 10000 kJ of energy. About 10% of the energy passes to each next level. How much energy reaches the secondary consumers, in kJ? → 100 kJPrompt: 10% means divide by 10 at each step.
3. Is a caterpillar a producer, a consumer or a decomposer? (producer / consumer / decomposer) → consumerPrompt: Does it make food, eat living things, or break down dead things?

• Show a food web and ask what would happen if one animal disappeared.
• Share the objective: The carbon cycle. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Does this process remove carbon dioxide from the air or add it: decomposition by microorganisms?
• Step 1: Respiration, combustion and decomposition release carbon dioxide.
• Step 2: So the answer is: adds CO₂ to the air
• Answer: adds CO₂ to the air
• Pause after each step and ask a student to say what comes next.

• Do these together. Students try each step on whiteboards before you reveal it.
• Use the hints as prompts rather than giving the answer.

1. Does this process remove carbon dioxide from the air or add it: carbon dioxide dissolving in the sea? (removes CO₂ from the air / adds CO₂ to the air) → removes CO₂ from the airPrompt: Which process do green plants use to make glucose?
2. How did fossil fuels such as coal form? (from seawater evaporating / from the remains of ancient plants buried and compressed over millions of years / from melted rock / from volcanoes erupting last century) → from the remains of ancient plants buried and compressed over millions of yearsPrompt: Coal contains carbon that plants once took from the air.

• Students work on the student sheet. Circulate and check the first two answers of every student early.
• Students who finish: write a question of their own for a partner, with the answer.

The 6 questions are on the student sheet below, with answers in the key.

• Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.

1. Does this process remove carbon dioxide from the air or add it: burning forests? (removes CO₂ from the air / adds CO₂ to the air) → adds CO₂ to the airPrompt: Which process do green plants use to make glucose?
2. Which process adds carbon dioxide to the air? (algae growing in the ocean / decomposition by microorganisms / carbon dioxide dissolving in the sea / trees growing) → decomposition by microorganismsPrompt: Which processes use up carbon dioxide, and which make it?

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-9.