The range is the difference between the highest and lowest values in a set of numbers. To find the median your numbers have to be listed in numerical order from smallest to largest so you may have to rewrite your list before you can find the median. Cross out values until you find the two centermost points and then calculate the average the two values.
Lets say your best score all year was a 100 and your worst was a 75.
It can be easier to identify the highest and lowest number in the set if you list the numbers in ascending order. The range of a set of data is the difference between the highest and lowest values in the set. First we will find the median of a set with an odd number of values. So a tree that is 260 cm tall is added to the 250-300 range.