BENEFITS AND DOWNFALLS OF PERCENTAGE
Percentage represents the proportions of known values. By using a percentage to represent the data you provide the reader with an easy to read summary statistic. There can be downfalls of using the percentage. Percentages are not additive, as each percentage calculation is worked out on the new value. For instance, and 10% pay rise followed by a 10% wage cut results in an overall pay decrease, since the wage cut is based on a larger number then the original number the wage rise was based on.
Similarly, a shop giving 50% off all stock with a further 50% off selected items does not mean the selected items are free.