We can model the orbits of the planets, the flow of blood through an artery, the trajectory of a ball thrown in the air, and countless other phenomena. But as we do so, the Christian mathematician has an excellent opportunity to simultaneously honor the Creator and exhibit the limitations of the creature. First, modeling of many phenomena, like atmospheric conditions and weather patterns, ignores many variables. Because of the complexity of the creation, we are forced to simplify our models to a great degree in order to get a handle on them. In this we see how little man understands compared to the knowledge of God.
Most mathematical methods are indeed approximative.
We can approximate desired values with as much accuracy as is deemed necessary and then minimize the error. However, we must admit that there is often some error in the process. All mathematics is based on a set of axioms, whether it be Peano's for arithmetic or Euclid's for Euclidean geometry. Our students need to see this distinction between absolute truth and truth based on axioms. Although mathematics is one of the purest of sciences, it is based on an axiom system or belief system and, therefore, does not generate absolute truths.