Geography K–10 · Years 9–10
Population pyramid from Census data and a growth model checked against the ABS
NSW Stage 5 focus area Changing Places (2015 syllabus) and Changing places (2024 syllabus); ACARA v9 teaches population change and migration in Year 8 (Changing nations), outside this entry's Years 9 and 10, so only Year 9 skills codes are listed
This site has no interactive model of its own. Where a step or a material names a Concept Studio model, simulation or tool, it has not been built; an external simulation a step names (for example PhET) is not part of this site.
The idea
A population's age and sex structure is drawn from counts, and its growth rate compounds, so a small annual percentage doubles a population within decades.
What you need
- ABS 2021 Census data for the school's suburb and for Australia: persons by five-year age group and sex (Census QuickStats and the General Community Profile), copied into a spreadsheet
- ABS National, state and territory population, reference period March 2026, released 17 September 2026: Australia 27 921 150 people at 31 March 2026, annual growth 1.4 %, natural increase 100 600, net overseas migration 292 100 (read 22 September 2026)
- Graph paper or a spreadsheet; calculator
How to do it
- Convert each five-year age group to a percentage of the suburb's total; draw males to the left and females to the right as horizontal bars.
- Repeat for Australia and place the two pyramids side by side on the same percentage scale.
- Compute the share aged under 15, 15 to 64 and 65 and over; dependency ratio = (under 15 + 65 and over) ÷ (15 to 64).
- From the ABS release, compute the share of the year's growth that came from net overseas migration: 292 100 ÷ (100 600 + 292 100).
- Compute the annual growth rate from the ABS figures, r = 392 700 ÷ (27 921 150 − 392 700), rather than using the rounded 1.4 %; project the population 10 years ahead at that rate compounded and compute the doubling time.
- Describe the suburb's pyramid against Australia's (a bulge of young adults, a narrow base, a wide top) and connect it to migration or ageing.
What you should see
Two pyramids in percentages, a dependency ratio for each, and computed growth figures: net overseas migration was 74.4 % of Australia's growth in the year to March 2026; at the rate the ABS components give (1.4265 % a year, which the ABS rounds to 1.4 %) the population reaches 32.17 million in 10 years and doubles in 48.9 years, where the rounded 1.4 % would give 32.09 million and 49.9 years. The suburb pyramid differs from the national one in a way the learner names from the bars. It worked if the pyramid bars sum to 100 % and the projection compounds rather than adding a fixed number each year.
What changes
This activity lists no variables to change, measure and keep the same.
Common misconceptions
Each of these ideas is wrong, and the activity is a chance to test it.
- A 1 % growth rate adds the same number of people every year.
- Australia's population growth comes mostly from births.
Safety card
Hazards
No hazard is listed.
Controls
No control is listed.
Note
No chemicals or heat are used. The activity is run under the school risk-assessment procedure; RiskAssess (riskassess.com.au) holds templates for school practicals and fieldwork. The NSW Department of Education Chemical Safety in Schools package is not triggered.
Curriculum references
The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.
- Geography K–10 Syllabus (2015), NESA; current and taught in 2026, replaced from 2027. The outcome codes are not printed on the NESA landing page for this syllabus, which only links the document, so the url given is the syllabus document itself (geography-k-10-syllabus-2015.docx); the code and its outcome text were read in that document on 23 September 2026.GE5-2GE5-3GE5-7
- Geography 7–10 Syllabus (2024), NESA; implementation from 2027, not yet taught; code read on this page on 22 September 2026GE5-PRI-01GE5-TAP-01
- Australian Curriculum v9AC9HG9S02AC9HG9S03
Sources
The pages the author read to write this activity.
- www.abs.gov.au/statistics/people/population/national-state-and-territory-population/latest-release
- www.abs.gov.au/statistics/people/population/population-clock-pyramid
- www.abs.gov.au/census/find-census-data/quickstats
- education.nsw.gov.au/teaching-and-learning/curriculum/hsie/hsie-curriculum-resources-k-12/hsie-7-10-curriculum-resources/geography-s5-changing-places
- curriculum.nsw.edu.au/learning-areas/hsie/geography-7-10-2024/outcomes