How to Find the Median of a Series of Numbers. Part of the series: Math Problems & History. Find the median of a series of numbers by ordering the numbers from lowest to highest and finding the number in the middle. If there is an even amount of numbers in a series, determine the average of the two middle numbers to find the median. Learn more about finding the median with information from a math teacher in this free video math lesson. Read more: http://www.ehow.com/video_4754363_find-median-series-numbers.html