Would you agree with Plato that mathematics isn't created by man, but has always exists?

Answer 1

a rational person cannot conceive that 2+2 not = 4 in any world.

But you say created. If the Creator is in some sense reasonable (as our being made in His Image suggests) then this is related to the nature of God. Look up LOGOS, the single most unifying concept in Western civilization, both among the philosophers and the Biblical adherents.