Is a negative number greater than zero?
Positive numbers are greater than 0, and negative numbers are less than 0.
Is a negative number equal to zero?
There is a negative 0, it just happens to be equal to the normal zero. For each real number a, we have a number −a such that a+(−a)=0. So for 0, we have 0+(−0)=0. However, 0 also has the property that 0+b=b for any b.