Median 
1. Arrange in order of size
2. Find the middle value
eg. Heights of plants:
11cm; 5cm; 7cm; 3cm; 14cm; 8cm; 9cm
In order:
3cm; 5cm; 7cm; 8cm; 9cm; 11cm; 14cm
Median = 8cm
NB: If the middle lies between 2 values, find the average of those values
eg. Heights of plants:
11cm; 5cm; 7cm; 3cm; 14cm; 8cm
In order:
3cm; 5cm; 7cm; 8cm; 11cm; 14cm
Median
= 7.5cm