• Quick retrieval from earlier learning (Read a food web: who eats whom?). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Here is a pond food web. (An arrow points from the food to the animal that eats it.) algae → mayfly larva algae → tadpole pondweed → pond snail algae → pond snail mayfly larva → dragonfly larva tadpole → dragonfly larva mayfly larva → stickleback (small fish) dragonfly larva → stickleback (small fish) stickleback (small fish) → heron tadpole → heron Which of these does the tadpole eat? (dragonfly larva / stickleback (small fish) / heron / algae) → algaePrompt: Find the arrows that point TO this animal.
2. Here is a pond food web. (An arrow points from the food to the animal that eats it.) algae → mayfly larva algae → tadpole pondweed → pond snail algae → pond snail mayfly larva → dragonfly larva tadpole → dragonfly larva mayfly larva → stickleback (small fish) dragonfly larva → stickleback (small fish) stickleback (small fish) → heron tadpole → heron How many different animals in this web eat the pondweed? → 1Prompt: Count the arrows that start at this living thing.
3. Here is an ocean food web. (An arrow points from the food to the animal that eats it.) phytoplankton → zooplankton kelp (seaweed) → sea urchin zooplankton → herring sea urchin → sea otter herring → seal seal → orca herring → orca A disease kills most of the zooplankton. Which animal loses one of its foods? (orca / sea urchin / herring / sea otter) → herringPrompt: Which animals have an arrow coming from it?

• Show a food web and ask what would happen if one animal disappeared.
• Share the objective: Predict what happens when a food web changes. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Sea otters eat sea urchins, and sea urchins eat kelp. Hunters remove most otters. What happens to the kelp forest?
• Step 1: With fewer predators, urchin numbers rise and they overgraze the kelp.
• Step 2: So the answer is: Urchins increase and eat much of the kelp.
• Answer: Urchins increase and eat much of the kelp.
• 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. Wolves were brought back to Yellowstone National Park. Deer stopped overeating young trees along rivers. What does this show? (A change to one predator can affect plants and the whole ecosystem. / Trees grow only near wolves. / Wolves eat trees. / Deer and wolves never interact.) → A change to one predator can affect plants and the whole ecosystem.Prompt: Wolves hunt deer, and deer eat young trees.
2. True or false? Removing a predator can cause its prey to increase. (True / False) → TruePrompt: Follow the arrows to see who depends on whom.

• 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. True or false? Changing one population never affects others in the web. (True / False) → FalsePrompt: Follow the arrows to see who depends on whom.
2. What is a likely knock-on effect: warmer seas bleach coral reefs? (reef fish lose food and shelter / insect-eating birds have less food / rabbit numbers rise and more grass is eaten / birds that eat small fish have less food) → reef fish lose food and shelterPrompt: Who eats what was lost or added?

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-5.