The median is the middle score for a set of data that has been arranged in order of magnitude.
So order your vales, and then pick the middle record.
This works fine when you have an odd number of scores.
BUT
What happens when you have an even number of scores?
It is easy...
You would calculate the mean of the two middle records ..
in other words:
you simply have to add up the middle two scores and average the result.
I hope that helps!