How are mathematical proposition's true - what doctrine do you ent to?

I subscribe to the pragmatic theory of truth, which basically says "if it works, it's true". Our entire world functions with math as its backbone, to count money, to tell time, to make your computer work, etc. Since the world isn't falling apart, we can conclude pretty confidently that math works, and therefore it is true. Whether this truth has any foundation in reality is not important.