In this lesson, participants learn how to draw comparisons between one amount and another. The concepts of percent, percentage, and base are taught and the relationship of these concepts to each other. Participants also learn how to find percent, percentage, and base by using paper and pencil as well as with a calculator. In addition, the lesson explains the concepts of ratio and proportion. This lesson teaches how to identify and construct both a ratio and proportion. Participants also learn how to use proportions to convert measurements from English to metric units.