The Percent Concept

 

To explain the concept of percent

To apply percent as a unit factor

 

Percents express the amount of a single quantity (a portion) as compared to the entire sample. A percent is:

           

A ratio of a single quantity, to a total sample, all multiplied by 100.

 

            A dime is 10% of a dollar.

            A gram is .001% of a kilogram

 

Percent Unit Factors:

            A percent can be listed as parts per 100. 

 

            So a dime can be written as 10% of a dollar or 10/100 of a dollar.

 

            Here’s an example:

Apollo 11 traveled 394,000 km from Earth to land on the Moon.  How many Km did it travel when it was 15.5% of the distance?

 

By definition: 15.5% is 15.5 parts per 100 or 15.5/100.  Since we are dealing with Km, then it would be 15.5km/100km.  This has now become a unit factor to solve the problem.

 Mathematics lesson- percent coposition.  Stop by to see examples of percent composition and percentages as a unit factor