what is the average of 5,8,13,67,23?

There are various averages:

One is the mean:  this is found by adding all the numbers together and divide by the number of numbers:

                             (5 + 8 + 13 + 67 + 23) / 5   =   ?

Another is the median:  this is the middle number when they are arranged by size:

                              What is the middle number in this sequence:  5, 8, 13, 67, 23?

Another is the mode:  this is the number used most often. In this case no number is used more often than the                                       rest, so there is no mode.