• Quick retrieval from earlier learning (How fossils form and what they reveal). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Fossils of tropical ferns have been found in Antarctica. What is the best explanation? (Antarctica has always been tropical / Ferns grow in ice today / The fossils were carried there by penguins / Antarctica was once in a warmer location, before plate movement carried it south) → Antarctica was once in a warmer location, before plate movement carried it southPrompt: Continents move slowly over millions of years.
2. Fossils: which statement is NOT true? (Insects can be preserved in amber (fossilised tree resin). / Fossils show that many species have become extinct. / Humans and dinosaurs lived at the same time. / Most living things that ever lived did not become fossils.) → Humans and dinosaurs lived at the same time.Prompt: Did people ever meet a living T. rex?
3. Footprints and burrows preserved in rock are called… (minerals / body fossils / trace fossils / crystals) → trace fossilsPrompt: They show the traces of activity, not the body itself.

• Pass round different rocks and ask how each one might have formed.
• Share the objective: Use rock layers to put events in order. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Undisturbed rock layers, listed from the bottom up: D, C, E. Which layer is the youngest?
• Step 1: In undisturbed layers, the lowest is oldest and the highest is youngest.
• Step 2: So the answer is: E
• Answer: E
• 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. Undisturbed rock layers, listed from the bottom up: A, B, D, E. Which layer is the youngest? (A / B / E / D) → EPrompt: Sediment settles on top of what is already there.
2. A crack filled with igneous rock (a dyke) cuts through layers A, B and C. What can you say about its age? (It is younger than all three layers / It is the same age as layer B / It is older than all three layers / Its age cannot be compared) → It is younger than all three layersPrompt: A layer must exist before something can cut through it.

• 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. Undisturbed rock layers, listed from the bottom up: A, C, D, B. Which layer is the youngest? (D / C / A / B) → BPrompt: Sediment settles on top of what is already there.
2. Rock layers are found tilted and folded. What does this tell you? (They formed on the Moon / They are igneous rock / They were laid down tilted / Forces moved the rock after the layers formed) → Forces moved the rock after the layers formedPrompt: Sediment settles in flat, horizontal layers.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-6.