Open with the Aboriginal story The Rainbow Serpent (Dick Roughsey). As you read, ask students to notice how the land changes — Goorialla makes rivers, creeks, hills and mountains. Draw out that a large mountain becomes a small hill, and ask: does Earth's surface really change like this? (Yes — but usually very slowly.)
Introduce weathering: rock broken into smaller pieces where it is. Using the slide deck, model the three types with a think-aloud — mechanical (ice widening a crack), chemical (acid rain dissolving rock), biological (tree roots, mining). Show an aerial map of the school with a timeline feature and note what has changed over the years.
In groups, students complete the Weathering and Erosion Match-Up (term → definition → example), then check and correct as a class. Then take the class outside for a weathering hunt: students photograph or record examples around the school — discoloured bricks, cracked paths from tree roots, worn steps — and, back inside, sort them into mechanical, chemical and biological on a class chart.
Students complete the Weathering Detectives worksheet: matching the three types to descriptions, classifying examples, drawing and explaining a weathering example they found, and explaining why weathering is slow and hard to notice.
Exit ticket: sort three given examples into mechanical, chemical or biological.