They are singular because mathematic and mathematics are the same thing, as well as physics; It's not like there are physic and physics.
No only the chef wears the hat.
It has to do with gender. The father feels the son is a mini version of him so he would rather teach him stuff that he never got to learn stuff like that.
Answer:
One is safe and civilized, and the other is savage.
Explanation:
This is the main difference between the setting of the Southern House and the setting of the train. The Southern House where Buck lives is comfortable and safe. This represents civilization, and all the things that this brings to dogs like Buck. On the other hand, as Buck gets away from the house, he also begins to get away from civilization and its comforts. The setting of the train contrasts with the house as it is a savage and uncivilized environment.
Mike and his mother.
His grandmother also plays a role as a major part of the story.