This is an original puzzle. It may require some specific knowledge, but nothing that can't be easily acquired.
ma(c + n + s) = ?
To steer you in the right direction, there are no acronyms involved.
Old MacDonald had a farm.
And on that farm he had a dog named Clifford,
And a cat named Nina,
But what was the name of his son?
Some subjects from highschool which you may find useful:
Mathematics initially, to set the stage;
Language or perhaps even history to understand what you see;
But physics and chemistry will not aid you here.