This article introduces the topic of how to teach the concept of metric by examples. Examples are data sets, taken from a larger set so that you can examine it to find out something about the larger set. We first introduce the theme and give a brief literature review on reasoning about examples and its application. Then we study how to teach the concept of metric and its application in cone metric. Finally, we give a remark on the development of teaching students to reason on examples.

example, mathematical education, metric, cone metric.