nvestigate why coastline length changes with measurement scale. A ready-to-use geography activity combining mapping, maths and fractal thinking.
Why does a coastline have no single, fixed length?
Students use the free Dig Earth Studio Coastline Paradox experiment to measure the same coastline using different ruler sizes and investigate how measurement scale changes the result.
They then compare smooth, rugged and very rugged coastlines, calculate changes in measured length and use their results to explain the relationship between scale, coastline complexity and measurement.
Included in the download:

• Student Activity Pack
• Full Answer Key
• Teacher Guide
• Data tables and calculation activities
• Extended-response questions
• Differentiation and teaching notes
• Final assessment quiz
• Link to the free Coastline Paradox interactive
  Students investigate:
• why measured coastline length depends on ruler size
• scale and map resolution
• coastline roughness and complexity
• percentage change
• patterns in measurement data
• power-law relationships and the idea of fractal dimension
• why measurements depend on the method and scale used
  Students move through a structured predict → measure → compare → explain investigation, using their own measurements as evidence.
  The interactive runs in a browser with no login required.
  Suitable for secondary Geography and Mathematics, particularly around ages 14–16. The activity can also support lessons on maps, scale, data analysis and mathematical modelling.
  Suggested teaching time: 45–60 minutes.
  The Coastline Paradox interactive itself is free to use. This resource provides the structured classroom investigation, calculations, questions, answers and teacher guidance needed to turn it into a complete lesson.