In quantile classes, we try to place an equal number of units into each class. This can be done most easily by ranking the data in ascending order. The size of the class is determined by taking the number of units and dividing it by the number of classes desired. For example, if we have 100 counties and we would like 5 classes (100/5) then there would be 20 counties in each class. The lowest 20 counties would be placed into the first class, the next 20 counties into the second and so on. The cartographer must make decisions when the number of classes does not divide evenly into the number of units. An attempt is usually made to spread any resulting uneveness among the classes.