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Geography K–10 · Years 5–6

Latitude, longitude and the shortest route: string on a globe against a flat map

Geography (HASS F–6 sub-strand); NSW Geography K–10 (2015) Stage 3 focus area: A Diverse and Connected World (Diversity across Asia: countries of the Asia region in relation to Australia); the NSW Stage 3 geographical tools name location, latitude, direction and distance, and longitude first appears in the Stage 4 list, so longitude and great-circle distance rest on ACARA Year 6 (AC9HS6K04, whose elaborations include locating places in the Asia region by latitude and longitude)

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The idea

Latitude and longitude fix any place on the globe, and the shortest route between two places is a great circle, which a string pulled tight on a globe follows and a straight line on a flat map does not.

What you need

  • 1 classroom globe per group; measure and record its diameter (for example 30 cm)
  • 1 m of thin string, a ruler, sticky dots
  • An atlas with a latitude and longitude grid and a world map on a flat projection with a scale bar
  • A list of 6 capitals in the Asia region (for example Jakarta, Dili, Bangkok, Manila, Tokyo, New Delhi) plus Sydney

How to do it

  1. Read each city's latitude and longitude from the atlas index to the nearest degree and write them in a table (south and east marked).
  2. Find each city on the globe from its coordinates alone and mark it with a dot; check the dot against the country outline.
  3. Wrap the string once around the globe's equator and measure the length: on a sphere of Earth's mean radius the equator is 40 030 km (the real equator is 40 075 km because Earth bulges, a difference of 0.1 %), so km per cm of string = 40 030 ÷ that length.
  4. Stretch the string tight between Sydney and each capital; measure the length and convert to km.
  5. Measure the same pairs on the flat world map with the ruler and its scale bar.
  6. Enter the coordinates in the calculator and compare its great-circle distance with the globe string and the flat-map value for each pair.

What you should see

A table of coordinates and three distances per pair. String distances on the globe are expected to agree closely with the computed great-circle distances, and the flat-map distances to differ more, most for long routes and routes far from the equator. For a 30 cm globe the equator is 94.2 cm of string, so 1 cm of string is 425 km; Sydney (33.87° S, 151.21° E) to Jakarta (6.21° S, 106.85° E) is 5496 km, or 12.9 cm of string. It worked if every city was found on the globe from its coordinates before looking at its name.

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.

  • The shortest route between two places is the straight line on a flat map.
  • Lines of longitude are the same distance apart everywhere.
  • Places north of Australia are all at the same latitude as each other.

Safety card

Low riskLearners carry it out

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.GE3-1GE3-4
  • Australian Curriculum v9AC9HS6K04AC9HS6S02AC9HS6S07

Sources

The pages the author read to write this activity.

  1. nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html
  2. www.ga.gov.au/education/classroom-resources/map-reading-guide
  3. education.nsw.gov.au/teaching-and-learning/curriculum/hsie/hsie-curriculum-resources-k-12/hsie-k-6-curriculum-resources/hsie-s3-units
  4. www.nsw.gov.au/education-and-training/nesa/curriculum/hsie/geography-k-10-2015

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