This is the Formalist philosophy of mathematics, which isn't the only one (as you might imagine given that it has a name):
http://plato.stanford.edu/entries/formalism-mathematics/
Formalism is at odds with Platonism, to pick an obvious antithesis, as Platonism holds that mathematical entities do indeed have a reality beyond us finite, mortal creatures and our symbols:
http://plato.stanford.edu/entries/platonism-mathematics/
There are, as you might imagine, a lot more philosophies of mathematics:
http://en.wikipedia.org/wiki/Philosophy_of_mathematics
That said, at the K-12 level, formalism is what students need most; make mathematics a game and show them how well the game applies to reality. That unreasonable effectiveness is quite astounding the first million times, and it never really quits being astounding:
http://www.dartmouth.edu/~matc/MathDrama/reading/Wigner.html
http://en.wikipedia.org/wiki/The_Unreasonable_Effectiveness_...