What is the median number for the numbers 4,8,10,5,9?

The median for a set of numbers would be the one that appears closest to the middle of the set.

For the set 4, 8, 10, 5, 9, in order to find the median, we must first sort them numerically.

4, 5, 8, 9, 10

Now, which of these 5 numbers is the closest to the middle?
The answer to that would be 8, since it is actually the number in the middle.

The median number for the numbers 4, 8, 10, 5, 9 is 8.
Hope that helped =)