What Is the Longitude of the Prime Meridian?

About this printable What Is the Longitude of the Prime Meridian? reading passage (Grades 3-7)

This passage explains that the *Prime Meridian* is the line of *0 degrees longitude* that divides the Earth into the *Eastern* and *Western Hemispheres*. It goes through *Greenwich, England*, and is the starting point for measuring all other lines of *longitude*. Students learn how this line helps us read maps, set time zones, and use GPS. The passage is aligned with Florida standard FL.SS.2.G.1.1 and helps children understand how Earth's geography is measured from east to west.

Written by Workybooks TeamPublished by Workybooks

Sample passage and quiz from What Is the Longitude of the Prime Meridian?

What Is the Prime Meridian?

The prime meridian is the starting line for measuring how far east or west a place is on Earth. By definition, the prime meridian has a longitude of 0° (zero degrees). Longitude tells us how far a location is from this line, measured in degrees.

What Does Longitude Mean?

Longitude lines are imaginary lines running from the North Pole to the South Pole. They do not cross each other and help us mark places on the Earth. The prime meridian splits the world into an eastern half and a western half. Places to the east of the prime meridian have positive longitude numbers, up to 180°E. Places to the west have negative numbers, up to 180°W. On the opposite side of the Earth from the prime meridian is the International Date Line at 180°.

How Does the Grid System Work?

The Earth is covered with a grid system made of longitude (east-west) and latitude (north-south) lines. Every location on Earth has a unique coordinate—its own 'address.' For example, New York City is about 74°W longitude and 41°N latitude.

What Are Degrees, Minutes, and Seconds?

Longitude is measured in degrees, but it can also be broken down into smaller parts called minutes and seconds. This helps people find locations very exactly, just like measuring feet and inches instead of just feet.

Why Does 0° Matter?

The prime meridian at 0° longitude is important because it gives everyone the same starting point for measuring. This system helps GPS devices, maps, pilots, and sailors find places anywhere in the world. Before 1884, different countries used different starting lines, which caused confusion. Now, everyone agrees on 0° as the starting line.

Making Connections

Try looking up your town’s longitude! Cities like Greenwich, England, and some places in Africa are right on 0° longitude. Zero degrees longitude is like the start of a measuring tape—the place where everyone begins counting east and west!

Interesting Fact: The prime meridian was chosen at a meeting in 1884 in Washington, D.C. Before that, maps and clocks could be very confusing!