Of or pertaining to mathematics; according to mathematics; hence, theoretically precise; accurate; as, mathematical geography; mathematical instruments; mathematical exactness.
of or pertaining to or of the nature of mathematics; "a mathematical textbook"; "slide rules and other mathematical instruments"; "a mathematical solution to a problem"; "mathematical proof"
The mathematical model is a set of relationships between observations on the one hand and the unknowns on the other. If there were no errors, the observations should fit the mathematical model exactly.