Using a number scale, especially on a map, is a straightforward process designed to translate distances shown on the map into real-world distances. To use the number scale, you need to measure a distance on a map using your ruler, and then multiply that measurement by the “real” part of the scale ratio (like 50) given on the map, in order to get the real distance.
Understanding the Number Scale
A number scale, also known as a ratio scale, represents the relationship between a distance on the map and the corresponding distance in the real world. It is typically expressed as a ratio, such as 1:50, 1:100,000, or 1:1,000,000.
- The first number (usually 1) represents a unit of distance on the map.
- The second number represents the same unit of distance in the real world.
For example, a scale of 1:50 means that 1 centimeter (or inch, or any unit) on the map represents 50 of the same units in reality.
Practical Steps for Using a Number Scale
Based on the provided method, here's how to calculate real-world distances using a number scale found on a map:
- Locate the Scale: Find the number scale displayed on your map. It will look something like 1:50, 1:100,000, etc.
- Measure the Distance: Using a ruler, carefully measure the distance between two points on the map that you are interested in.
- Identify the "Real" Part: Note the second number in the scale ratio. This is the "real" part that tells you how many real-world units are represented by one map unit (e.g., 50 in a 1:50 scale).
- Calculate Real Distance: Multiply the distance you measured on the map by this "real" part of the scale ratio. The result will be the real-world distance in the same units you used to measure on the map.
Example Calculation
Let's assume your map has a number scale of 1:50, and you've measured a distance between two points on the map to be 5 centimeters (cm).
- Map distance = 5 cm
- "Real" part of the scale = 50
Real Distance = Map distance × "Real" part of the scale
Real Distance = 5 cm × 50
Real Distance = 250 cm
So, the real distance between those two points is 250 cm, which is equivalent to 2.5 meters.
This method allows you to accurately determine actual distances on the ground by taking simple measurements from a scaled representation like a map.
