Erect means build or upright. If you erect a house, you build it. If you stand erect, you hold your body as tall as possible.
A mathematical model is a description of a system using mathematical concepts and language.The process of building a mathematical model is termed mathematical modeling.Mathematical models are used in the natural sciences (such as physics, biology, earth science, meteorology) and engineering disciplines (e.g. computer science, artificial intelligence). mathematical model is a description of a system using mathematical concepts and language.
The entire game is pretty much all math when you think about it. Newtonian physics are heavily simulated in KSP. Without the use of math in KSP, the game wouldn't be able to do much. Your rocket wouldn't be able to get off the ground and out of the atmosphere into space.