Why is the oxidation number of sulfur in H2SO3 = +4 and equal to -2 in H2S?

I can't seem to find how this works with the oxidation rules.

Question

Why is the oxidation number of sulfur in H2SO3 = +4 and equal to -2 in H2S? 

I can't seem to find how this works with the oxidation rules.

sweetburger · Answer

That seems correct. Just so you know elements can take on numerous different oxidization numbers.

anonymous · Answer

@sweetburger haha, it is correct, i just want to know why it is?

sweetburger · Answer

Man, I don't really know how to explain why atoms take on different  oxidization numbers. 
I'll research it right now.

sweetburger · Answer