What is the median? what does this value mean?

The median is 2. The median is the middle of the data set.

You can determine if two numbers are equal if they have the same value. (4 are 4 are equal) (4 and 5 are not equal). You can determine if two expressions are equal by solving them. If the answers are of an equal value, they are equal. (4+5 and 6+3 are equal because they both work out to be 9) (4+5 and 5+5 are not equal because they work out to be 9 and 10.)
                                              ~Crutchie
p.s. The mathmatical term for "equal" is equivilent. As in equivilent expressions or equivilent numbers.

p.p.s. The mathmatical term for "numbers" are integers. As in the diffrence between the integers or equivilent integers.