[Jcrew]

I think sklansky considers problems that exist on a purely abstract universe as math problems but not its applications to the real world. One characteristic of sklansky classified math problems(SCMP) is that they can be either true or false based on a set of axioms(so this includes logic).

Math is applied to the real world in the form of models. Models are neither right or wrong but are just description of behavior. They are accurate/inaccurate in various degrees. Except some models might be exact like a model that simply counts a quantity. Not sure how would classify that under (SCMP).