• Quick retrieval from earlier learning (Food webs and interdependence). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Woodland food web: grass is eaten by rabbits and mice. Seeds are eaten by mice. Rabbits are eaten by foxes. Mice are eaten by foxes and owls. If disease killed most rabbits, what might happen to the mice? (They become rabbits / They increase, because foxes stop eating / Their numbers fall, because foxes eat more mice / They stop eating seeds) → Their numbers fall, because foxes eat more micePrompt: Foxes still need to eat.
2. Bees are declining. Why could this affect fruit farmers? (Fruit trees need honey to grow / Fewer flowers would be pollinated, so less fruit forms / Bees make the rain / Bees eat fruit) → Fewer flowers would be pollinated, so less fruit formsPrompt: What do bees carry between flowers?
3. Food webs: which statement is NOT true? (Removing a predator always helps every other species. / Animals often compete for food, water and space. / Removing one species can affect many others in a food web. / Plants compete for light, water and minerals.) → Removing a predator always helps every other species.Prompt: Think about what happens when one population changes.

• Show a food web and ask what would happen if one animal disappeared.
• Share the objective: Sampling with quadrats. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Five 1 m² quadrats contained these numbers of daisies: 7, 4, 11, 4, 10. What is the mean number of daisies per quadrat?
• Step 1: (7 + 4 + 11 + 4 + 10) ÷ 5 = 7.2
• Step 2: So the answer is: 7.2
• Answer: 7.2
• 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. Five 1 m² quadrats contained these numbers of daisies: 7, 10, 4, 2, 6. What is the mean number of daisies per quadrat? → 5.8Prompt: Add up all the counts.
2. The mean number of buttercups in a 1 m² quadrat is 7. The field is 250 m². Estimate the number of buttercups in the field. → 1750Prompt: How many quadrats would fit in the field?

• 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 8 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. Which is an abiotic factor? (number of predators / light intensity / competition from other plants / a new disease) → light intensityPrompt: Abiotic means non-living.
2. Five 1 m² quadrats contained these numbers of daisies: 0, 11, 1, 0, 4. What is the mean number of daisies per quadrat? → 3.2Prompt: Add up all the counts.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-10.