Alright, I know how to assign oxidation numbers but not with compounds involving 3 elements.

Well, I do know how to assign the numbers for H2SO4 [H=1, S=+6, O=-2] but that is because its almost always that H is -1 and O is -2. But how would I assign the numbers for PbSO4

I know O is going to be -2, but what about S and Pb?

Thanks.