Use High School Math Information to Teach the “Rule of 82” and its applications

Columnist: Dr. Matthew Yip (Mathematician Prof.)

The “80-20 rule” means that the first 20% of the “effort” will get the first 80% of the “return”. Using the function to express the high school, first set the function to go through (0,0), (1,1) and (0.2,0.8), then take it as an exponential function, that is, .

Substituting and, we have , that is, . Therefore, , where , is a function that represents the “80-20 rule”.

Below is the activity graph:

After establishing an activity that represents the “80-20 rule”, examples can be used to deepen students’ understanding. The following is an example:

Consider that there are 10 million people in the world who are majoring in math education.

Their “influence” follows the “80-20 rule”. The “influence” of the most “influential” person must cause the “influence” of all people. What percentage of “power”?

We only need to replace find , which means that the “influence” of the “powerful” person exceeded 10%!

This example allows students to experience the magic of the “80-20 Rule”!

For other extensions of the “80-20 rule”, see “Combining “Single Points” and “the 80-20 rule.”