Population change has three moving parts: births, deaths and migration. This hub shows how they add up, how age structure shows the result, and how to write about effects fairly.
It belongs to population and settlements. If density is your weak point, see population distribution and density first.
How does total change add up?
Split the change in two, then add. Natural increase is births minus deaths. Net migration is people who moved in minus people who moved out.
Here is an original town. It starts at 10 000 residents. In a year there are 200 births, 80 deaths, 300 in-migrants and 100 out-migrants.
- Natural increase: 200 − 80 = 120.
- Net migration: 300 − 100 = 200.
- Total change: 120 + 200 = 320, so the town ends at 10 320.
Migration gave the town more growth than births did, and a sentence that credits only births would be wrong.
Which lesson should you start with?
| If this happens to you | Start with |
|---|---|
| Total change looks right but you cannot say why | Separating natural change from net migration |
| Pyramid questions feel like guessing | Interpreting an original population pyramid |
| You compare two towns, but their age groups do not match | Comparing age structures with the same categories |
| Your effects paragraph sounds like blame | Explaining effects without stereotyping |
How should you practise?
Work one lesson, then attempt the mixed practice set. The graph evidence and fair-comparison lab lets you test whether a comparison between two towns is fair.
Who should start where?
A student who mixes up growth and migration should start with the first lesson and stay there until the addition is automatic. A student who reads numbers well but writes vague effects can start at the last lesson.
If you want a teacher to check your figures and your wording, see online one-to-one Geography tuition.