Map Grids and Finding Locations: Second Grade Social Studies

A map grid is a network of intersecting horizontal and vertical lines that creates labeled squares, allowing us to pinpoint exact locations quickly and accurately.

What Is a Map Grid?

Have you ever tried to find a small playground on a large map filled with hundreds of streets and buildings? Without a system, you might spend ten minutes scanning back and forth with your eyes. Geographers solve this challenge by placing a grid over the map.

How a Grid Works

A grid is made by drawing straight lines from top to bottom (vertical lines) and straight lines from left to right (horizontal lines). Where these lines cross, they form a checkerboard pattern of boxes called grid squares.

        A           B           C           D
   +-----------+-----------+-----------+-----------+
 1 |  House    |           |   Park    |           | 1
   +-----------+-----------+-----------+-----------+
 2 |           |  School   |           |  Library  | 2
   +-----------+-----------+-----------+-----------+
 3 |   Store   |           |   Pond    |           | 3
   +-----------+-----------+-----------+-----------+
        A           B           C           D

Letters and Numbers as Coordinates

To identify each square, mapmakers label the columns across the top with letters (such as A, B, C, D) and the rows down the side with numbers (such as 1, 2, 3). A coordinate is the pair of a letter and a number that identifies one specific box on the grid.

When giving coordinates, we always say the column letter first, followed by the row number. For example, in the grid above, the School is located at coordinate B2.

Finding Features Using Coordinates

Using coordinates is like following two invisible paths until they meet.

Step-by-Step Method for Locating Coordinates

To find an object at coordinate C1, follow two simple steps. First, look across the top of the grid and find the letter C. Place your finger on column C. Second, look down the left side and find the row marked 1. Slide your finger down column C until it lines up with row 1. That box is C1, where you will find the Park.

   Step 1: Find Column C across the top.
   Step 2: Move down to Row 1.
   Intersection (C, 1) = [ C1: Park ]

Reading the Map in Reverse: Finding an Object's Coordinate

You can also do the process in reverse to find the coordinates of an item. To find the location of the Pond in our diagram: first, locate the Pond with your eyes; second, look straight up to see which column it sits in (Column C); third, look straight to the left to see which row it sits in (Row 3). Combine the letter and number: the Pond is located at C3.

Grid Coordinates Practice Table

Let us analyze all the features shown on our sample community map grid:

+---------------------+-------------------+-------------------+
| MAP FEATURE         | COLUMN & ROW      | GRID COORDINATE   |
+---------------------+-------------------+-------------------+
| House               | Column A, Row 1   | A1                |
| Park                | Column C, Row 1   | C1                |
| School              | Column B, Row 2   | B2                |
| Library             | Column D, Row 2   | D2                |
| Store               | Column A, Row 3   | A3                |
| Pond                | Column C, Row 3   | C3                |
+---------------------+-------------------+-------------------+

Empty Grid Squares

Notice that some squares, such as A2, B1, and D3, do not have any labeled buildings. In a real community map, these squares might contain open fields, parking lots, residential yards, or roads passing through. Every square has an address, even if it is currently open space.

Real-World Applications of Grid Systems

Grid systems are used everywhere around us, from amusement park guides to emergency rescue systems.

City Street Grids

Many major cities, such as New York, Chicago, and Salt Lake City, were designed using grid street plans. Avenues run north and south, while streets run east and west, numbered in sequential order. If you are on 4th Avenue and 20th Street and need to walk to 4th Avenue and 25th Street, you simply walk five blocks north.

Latitude and Longitude: Earth's Global Grid

When geographers look at the entire Earth, they use a massive grid system called latitude and longitude. Lines of latitude run horizontally around Earth parallel to the Equator. Lines of longitude run vertically from the North Pole to the South Pole. Together, these global coordinates allow airplane pilots and ship captains to pinpoint any spot on Earth, even in the middle of a vast ocean.

Exercises and Review

Exercise 1: Explain how vertical and horizontal lines work together to create coordinates on a map grid, and state the rule for which character comes first in a coordinate.

Exercise 1 Solution: Vertical lines running from top to bottom and horizontal lines running from side to side cross each other to form a pattern of square boxes. The columns across the top are labeled with letters, and the rows down the side are labeled with numbers. The rule for writing a coordinate is that the column letter always comes first, followed by the row number, such as A1 or B3.

Exercise 2: Look at the sample map grid provided in this chapter. What feature is located at coordinate D2, and what is the exact coordinate for the Store?

Exercise 2 Solution: Looking at the sample grid, the feature located at coordinate D2 is the Library, which sits in Column D and Row 2. The exact coordinate for the Store is A3, which sits in Column A and Row 3.