Average is a number that is typical of a group of numbers. People usually think of an average as a mean. A mean is the sum of a group of numbers divided by the number of numbers. For example, the average, or mean, of 4, 5, 6, 7, and 8 is 6, or 30 divided by 5. Other numbers are also typical of a group of numbers. A median is the middle number of a series of numbers arranged in numerical order, if there is an odd number of numbers. If the number of numbers is even, the median is the mean of the middle two numbers. A mode is the number that occurs most often in a group. See also Mean; Median; Mode; Statistics.