Year 4 Science – Term 3 (WA Curriculum): How Earth's Surface Changes Over Time

What this unit covers

In Term 3, Year 4 Science in the WA Curriculum centres on the unit “How Earth's Surface Changes Over Time”.

Students explore how weathering, erosion, transportation and deposition processes cause both slow and rapid changes to Earth's surface, including the formation of significant landforms.

Lesson sequence (8 lessons)

The unit breaks down into the following lesson-by-lesson sequence — each title below is a teachable lesson, in order:

1. Investigating How Wind and Water Break Down Rocks
2. Exploring Chemical Weathering and Acid Rain Effects
3. Discovering How Plants and Animals Change Earth's Surface
4. Observing Erosion in Action Through Water Experiments
5. Creating Sand Dunes to Model Wind Transportation
6. Building Canyons and Caves in the Classroom
7. Exploring Sacred Landforms: Wave Rock and Noongar Culture
8. Comparing Fast and Slow Earth Surface Changes

Curriculum codes in this unit

Content codes:

Reading the codes: WA codes (the ones starting with WA) pack the year level, learning area, strand and content number into one string, while the national Australian Curriculum v9 uses a different anatomy that starts with AC9 — same content family, different labels. Our complete WA Curriculum guide decodes both, character by character.

Planning notes for Term 3

WA terms run roughly 9–11 weeks, and in 2026 Term 3 runs from Monday 20 July to Friday 25 September — 10 weeks for WA public schools. With 8 lessons in this unit, that leaves breathing room for assessment, moderation and the weeks that disappear to carnivals, camps and public holidays — plan the assessable work to land two to three weeks before the end of term rather than in the final week.