For example, the ratio of eighth graders at Smith Middle School who are in the school band (40) to those who are not in the school band (110) can be represented by the partpart ratio, 40/110. In this example, the "whole" is the number of eighth graders at Smith Middle School. One "part" of them is in the school band, and the other "part" is not; these "parts" are the numbers that are used to make the ratio.
