Scale is a measurement between any two points or objects. We need scale to tell how far apart things really are from each other because a life size map wouldnt be very practical! Scale uses smaller measurements to represent larger measurements. If you were looking at a globe the scale would be much different that if you were looking at a house plan. On a globe, the scale might be 1 inch equals 660 miles (3,484,800 feet). On a house plan, the scale might be 1 inch equals 2 feet. Mapmakers decide what scale according to the size of the map or plan and for what the map or plan will be used.
To use scale, you need to use mathematics. The first thing you have to be able to do to use scale is to measure the distance between two places. Then you need to find out what the scale is. For example, it might measure 2 inches from Boston to Concord, if the scale were 1 inch equals 2,000,000 miles, then from Boston to Concord would be 4,000,000 miles. If the scale were 1/2 inch equals 3 miles then the towns would be 12 miles apart. As you can see, the scale can make a huge difference!
Map scale is the same thing as a mathematical ratio. A ratio is the relationship between two numbers and scale is the relationship between the distance between the measurement on the map and the actual distance between the two real places.