The arithmetic mean, also known as arithmetic average, is the sum of all the values in a list of numerical values divided by the number of items in the list. For example, if we have the two values, eight and six, then their arithmetic average is: 8 + 6 / 2 = 7.
In common daily usage, the term 'average' usually refers to the arithmetic mean rather than to the other types of average, such as the geometric mean, harmonic mean, median or mode.