Now turn it around: someone gives you coordinates, and you find the place. This is how ships, planes and rescuers find a spot on a map. You will use what you learned in Reading Coordinates.
Key idea
Find the latitude first (go up for N, down for S from the equator), then move along that parallel to the longitude (right for E, left for W of the prime meridian). The place is where the two lines cross.
Worked example: Find 35° N, 140° E
Which big city is at about 35° N, 140° E?
- Start at the equator and go up (north) to 35° N, a little past the 30° line.
- Move right (east) from the prime meridian to 140° E, far into Asia.
- The lines cross on the island of Honshu, in Japan.
Answer: Tokyo, Japan.
Why it works
On almost every world map, north is at the top and east is on the right. So north latitudes grow upward from the equator and south latitudes grow downward; east longitudes grow to the right of the prime meridian and west longitudes grow to the left. Knowing which way the numbers grow is the whole trick.
Worked example: A southern city
Which city is at about 23° S, 43° W: Rio de Janeiro, Cairo or New York?
- 23° S is below the equator, so the city is in the Southern Hemisphere.
- 43° W is left of the prime meridian: the Americas or the Atlantic.
- Of the three, only Rio de Janeiro is south of the equator and in the Americas.
Answer: Rio de Janeiro, Brazil.
Common mistake
Counting the wrong way from 0°. West longitudes get bigger as you go left on the map, and south latitudes get bigger as you go down. A quick check: a place at 23° S, 43° W must be below the equator and left of the prime meridian. If your finger ends up in Africa or Asia, a letter was read backward.